| Index: third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp | 
| diff --git a/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp | 
| index cfeedd4c6bbd355bf8b39c708de3956c23141360..1c2b242686ddfa326f0731fffe2d3a4938ecb3b6 100644 | 
| --- a/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp | 
| +++ b/third_party/WebKit/Source/core/layout/LayoutBlockFlow.cpp | 
| @@ -75,27 +75,33 @@ static_assert(sizeof(LayoutBlockFlow::MarginValues) == sizeof(LayoutUnit[4]), | 
|  | 
| // Caches all our current margin collapsing state. | 
| class MarginInfo { | 
| -  // Collapsing flags for whether we can collapse our margins with our children's margins. | 
| +  // Collapsing flags for whether we can collapse our margins with our | 
| +  // children's margins. | 
| bool m_canCollapseWithChildren : 1; | 
| bool m_canCollapseMarginBeforeWithChildren : 1; | 
| bool m_canCollapseMarginAfterWithChildren : 1; | 
| bool m_canCollapseMarginAfterWithLastChild : 1; | 
|  | 
| -  // Whether or not we are a quirky container, i.e., do we collapse away top and bottom | 
| -  // margins in our container. Table cells and the body are the common examples. We | 
| -  // also have a custom style property for Safari RSS to deal with TypePad blog articles. | 
| +  // Whether or not we are a quirky container, i.e., do we collapse away top and | 
| +  // bottom margins in our container. Table cells and the body are the common | 
| +  // examples. We also have a custom style property for Safari RSS to deal with | 
| +  // TypePad blog articles. | 
| bool m_quirkContainer : 1; | 
|  | 
| -  // This flag tracks whether we are still looking at child margins that can all collapse together at the beginning of a block. | 
| -  // They may or may not collapse with the top margin of the block (|m_canCollapseTopWithChildren| tells us that), but they will | 
| -  // always be collapsing with one another. This variable can remain set to true through multiple iterations | 
| -  // as long as we keep encountering self-collapsing blocks. | 
| +  // This flag tracks whether we are still looking at child margins that can all | 
| +  // collapse together at the beginning of a block. They may or may not collapse | 
| +  // with the top margin of the block (|m_canCollapseTopWithChildren| tells us | 
| +  // that), but they will always be collapsing with one another. This variable | 
| +  // can remain set to true through multiple iterations as long as we keep | 
| +  // encountering self-collapsing blocks. | 
| bool m_atBeforeSideOfBlock : 1; | 
|  | 
| -  // This flag is set when we know we're examining bottom margins and we know we're at the bottom of the block. | 
| +  // This flag is set when we know we're examining bottom margins and we know | 
| +  // we're at the bottom of the block. | 
| bool m_atAfterSideOfBlock : 1; | 
|  | 
| -  // These variables are used to detect quirky margins that we need to collapse away (in table cells | 
| +  // These variables are used to detect quirky margins that we need to collapse | 
| +  // away (in table cells | 
| // and in the body element). | 
| bool m_hasMarginBeforeQuirk : 1; | 
| bool m_hasMarginAfterQuirk : 1; | 
| @@ -190,9 +196,10 @@ class MarginInfo { | 
| } | 
| }; | 
|  | 
| -// Some features, such as floats, margin collapsing and fragmentation, require some knowledge about | 
| -// things that happened when laying out previous block child siblings. Only looking at the object | 
| -// currently being laid out isn't always enough. | 
| +// Some features, such as floats, margin collapsing and fragmentation, require | 
| +// some knowledge about things that happened when laying out previous block | 
| +// child siblings. Only looking at the object currently being laid out isn't | 
| +// always enough. | 
| class BlockChildrenLayoutInfo { | 
| public: | 
| BlockChildrenLayoutInfo(LayoutBlockFlow* blockFlow, | 
| @@ -202,9 +209,10 @@ class BlockChildrenLayoutInfo { | 
| m_previousBreakAfterValue(BreakAuto), | 
| m_isAtFirstInFlowChild(true) {} | 
|  | 
| -  // Store multicol layout state before first layout of a block child. The child may contain a | 
| -  // column spanner. If we need to re-lay out the block child because our initial logical top | 
| -  // estimate was wrong, we need to roll back to how things were before laying out the child. | 
| +  // Store multicol layout state before first layout of a block child. The child | 
| +  // may contain a column spanner. If we need to re-lay out the block child | 
| +  // because our initial logical top estimate was wrong, we need to roll back to | 
| +  // how things were before laying out the child. | 
| void storeMultiColumnLayoutState(const LayoutFlowThread& flowThread) { | 
| m_multiColumnLayoutState = flowThread.multiColumnLayoutState(); | 
| } | 
| @@ -274,15 +282,17 @@ void LayoutBlockFlow::checkForPaginationLogicalHeightChange( | 
| bool& pageLogicalHeightChanged, | 
| bool& hasSpecifiedPageLogicalHeight) { | 
| if (LayoutMultiColumnFlowThread* flowThread = multiColumnFlowThread()) { | 
| -    // Calculate the non-auto content box height, or set it to 0 if it's auto. We need to know | 
| -    // this before layout, so that we can figure out where to insert column breaks. We also | 
| -    // treat LayoutView (which may be paginated, which uses the multicol implmentation) as | 
| -    // having non-auto height, since its height is deduced from the viewport height. We use | 
| -    // computeLogicalHeight() to calculate the content box height. That method will clamp | 
| -    // against max-height and min-height. Since we're now at the beginning of layout, and we | 
| -    // don't know the actual height of the content yet, only call that method when height is | 
| -    // definite, or we might fool ourselves into believing that columns have a definite height | 
| -    // when they in fact don't. | 
| +    // Calculate the non-auto content box height, or set it to 0 if it's auto. | 
| +    // We need to know this before layout, so that we can figure out where to | 
| +    // insert column breaks. We also treat LayoutView (which may be paginated, | 
| +    // which uses the multicol implmentation) as having non-auto height, since | 
| +    // its height is deduced from the viewport height. | 
| +    // We use computeLogicalHeight() to calculate the content box height. That | 
| +    // method will clamp against max-height and min-height. Since we're now at | 
| +    // the beginning of layout, and we don't know the actual height of the | 
| +    // content yet, only call that method when height is definite, or we might | 
| +    // fool ourselves into believing that columns have a definite height when | 
| +    // they in fact don't. | 
| LayoutUnit columnHeight; | 
| if (hasDefiniteLogicalHeight() || isLayoutView()) { | 
| LogicalExtentComputedValues computedValues; | 
| @@ -296,15 +306,17 @@ void LayoutBlockFlow::checkForPaginationLogicalHeightChange( | 
| } else if (isLayoutFlowThread()) { | 
| LayoutFlowThread* flowThread = toLayoutFlowThread(this); | 
|  | 
| -    // FIXME: This is a hack to always make sure we have a page logical height, if said height | 
| -    // is known. The page logical height thing in LayoutState is meaningless for flow | 
| -    // thread-based pagination (page height isn't necessarily uniform throughout the flow | 
| -    // thread), but as long as it is used universally as a means to determine whether page | 
| -    // height is known or not, we need this. Page height is unknown when column balancing is | 
| -    // enabled and flow thread height is still unknown (i.e. during the first layout pass). When | 
| -    // it's unknown, we need to prevent the pagination code from assuming page breaks everywhere | 
| -    // and thereby eating every top margin. It should be trivial to clean up and get rid of this | 
| -    // hack once the old multicol implementation is gone. | 
| +    // FIXME: This is a hack to always make sure we have a page logical height, | 
| +    // if said height is known. The page logical height thing in LayoutState is | 
| +    // meaningless for flow thread-based pagination (page height isn't | 
| +    // necessarily uniform throughout the flow thread), but as long as it is | 
| +    // used universally as a means to determine whether page height is known or | 
| +    // not, we need this. Page height is unknown when column balancing is | 
| +    // enabled and flow thread height is still unknown (i.e. during the first | 
| +    // layout pass). When it's unknown, we need to prevent the pagination code | 
| +    // from assuming page breaks everywhere and thereby eating every top margin. | 
| +    // It should be trivial to clean up and get rid of this hack once the old | 
| +    // multicol implementation is gone. | 
| pageLogicalHeight = | 
| flowThread->isPageLogicalHeightKnown() ? LayoutUnit(1) : LayoutUnit(); | 
|  | 
| @@ -322,8 +334,8 @@ void LayoutBlockFlow::setBreakAtLineToAvoidWidow(int lineToBreak) { | 
| void LayoutBlockFlow::setDidBreakAtLineToAvoidWidow() { | 
| ASSERT(!shouldBreakAtLineToAvoidWidow()); | 
|  | 
| -  // This function should be called only after a break was applied to avoid widows | 
| -  // so assert |m_rareData| exists. | 
| +  // This function should be called only after a break was applied to avoid | 
| +  // widows so assert |m_rareData| exists. | 
| ASSERT(m_rareData); | 
|  | 
| m_rareData->m_didBreakAtLineToAvoidWidow = true; | 
| @@ -346,9 +358,10 @@ void LayoutBlockFlow::clearShouldBreakAtLineToAvoidWidow() const { | 
|  | 
| bool LayoutBlockFlow::isSelfCollapsingBlock() const { | 
| if (needsLayout()) { | 
| -    // Sometimes we don't lay out objects in DOM order (column spanners being one such relevant | 
| -    // type of object right here). As long as the object in question establishes a new | 
| -    // formatting context, that's nothing to worry about, though. | 
| +    // Sometimes we don't lay out objects in DOM order (column spanners being | 
| +    // one such relevant type of object right here). As long as the object in | 
| +    // question establishes a new formatting context, that's nothing to worry | 
| +    // about, though. | 
| ASSERT(createsNewFormattingContext()); | 
| return false; | 
| } | 
| @@ -358,10 +371,12 @@ bool LayoutBlockFlow::isSelfCollapsingBlock() const { | 
|  | 
| bool LayoutBlockFlow::checkIfIsSelfCollapsingBlock() const { | 
| // We are not self-collapsing if we | 
| -  // (a) have a non-zero height according to layout (an optimization to avoid wasting time) | 
| +  // (a) have a non-zero height according to layout (an optimization to avoid | 
| +  //     wasting time) | 
| // (b) have border/padding, | 
| // (c) have a min-height | 
| -  // (d) have specified that one of our margins can't collapse using a CSS extension | 
| +  // (d) have specified that one of our margins can't collapse using a CSS | 
| +  //     extension | 
| // (e) establish a new block formatting context. | 
|  | 
| // The early exit must be done before we check for clean layout. | 
| @@ -371,9 +386,10 @@ bool LayoutBlockFlow::checkIfIsSelfCollapsingBlock() const { | 
| if (createsNewFormattingContext()) | 
| return false; | 
|  | 
| -  // Placeholder elements are not laid out until the dimensions of their parent text control are known, so they | 
| -  // don't get layout until their parent has had layout - this is unique in the layout tree and means | 
| -  // when we call isSelfCollapsingBlock on them we find that they still need layout. | 
| +  // Placeholder elements are not laid out until the dimensions of their parent | 
| +  // text control are known, so they don't get layout until their parent has had | 
| +  // layout - this is unique in the layout tree and means when we call | 
| +  // isSelfCollapsingBlock on them we find that they still need layout. | 
| ASSERT(!needsLayout() || | 
| (node() && node()->isElementNode() && | 
| toElement(node())->shadowPseudoId() == "-webkit-input-placeholder")); | 
| @@ -395,18 +411,20 @@ bool LayoutBlockFlow::checkIfIsSelfCollapsingBlock() const { | 
| } | 
| } | 
|  | 
| -  // If the height is 0 or auto, then whether or not we are a self-collapsing block depends | 
| -  // on whether we have content that is all self-collapsing or not. | 
| +  // If the height is 0 or auto, then whether or not we are a self-collapsing | 
| +  // block depends on whether we have content that is all self-collapsing. | 
| // TODO(alancutter): Make this work correctly for calc lengths. | 
| if (hasAutoHeight || ((logicalHeightLength.isFixed() || | 
| logicalHeightLength.isPercentOrCalc()) && | 
| logicalHeightLength.isZero())) { | 
| -    // If the block has inline children, see if we generated any line boxes.  If we have any | 
| -    // line boxes, then we can't be self-collapsing, since we have content. | 
| +    // If the block has inline children, see if we generated any line boxes. | 
| +    // If we have any line boxes, then we can't be self-collapsing, since we | 
| +    // have content. | 
| if (childrenInline()) | 
| return !firstLineBox(); | 
|  | 
| -    // Whether or not we collapse is dependent on whether all our normal flow children | 
| +    // Whether or not we collapse is dependent on whether all our normal flow | 
| +    // children | 
| // are also self-collapsing. | 
| for (LayoutBox* child = firstChildBox(); child; | 
| child = child->nextSiblingBox()) { | 
| @@ -474,16 +492,17 @@ inline bool LayoutBlockFlow::layoutBlockFlow(bool relayoutChildren, | 
| LayoutState state(*this, locationOffset(), pageLogicalHeight, | 
| pageLogicalHeightChanged, logicalWidthChanged); | 
|  | 
| -  // We use four values, maxTopPos, maxTopNeg, maxBottomPos, and maxBottomNeg, to track | 
| -  // our current maximal positive and negative margins. These values are used when we | 
| -  // are collapsed with adjacent blocks, so for example, if you have block A and B | 
| -  // collapsing together, then you'd take the maximal positive margin from both A and B | 
| -  // and subtract it from the maximal negative margin from both A and B to get the | 
| -  // true collapsed margin. This algorithm is recursive, so when we finish layout() | 
| -  // our block knows its current maximal positive/negative values. | 
| +  // We use four values, maxTopPos, maxTopNeg, maxBottomPos, and maxBottomNeg, | 
| +  // to track our current maximal positive and negative margins. These values | 
| +  // are used when we are collapsed with adjacent blocks, so for example, if you | 
| +  // have block A and B collapsing together, then you'd take the maximal | 
| +  // positive margin from both A and B and subtract it from the maximal negative | 
| +  // margin from both A and B to get the true collapsed margin. This algorithm | 
| +  // is recursive, so when we finish layout() our block knows its current | 
| +  // maximal positive/negative values. | 
| // | 
| -  // Start out by setting our margin values to our current margins. Table cells have | 
| -  // no margins, so we don't fill in the values for table cells. | 
| +  // Start out by setting our margin values to our current margins. Table cells | 
| +  // have no margins, so we don't fill in the values for table cells. | 
| if (!isTableCell()) { | 
| initMaxMarginValues(); | 
| setHasMarginBeforeQuirk(style()->hasMarginBeforeQuirk()); | 
| @@ -493,12 +512,13 @@ inline bool LayoutBlockFlow::layoutBlockFlow(bool relayoutChildren, | 
| if (state.isPaginated()) { | 
| setPaginationStrutPropagatedFromChild(LayoutUnit()); | 
|  | 
| -    // Start with any applicable computed break-after and break-before values for this | 
| -    // object. During child layout, breakBefore will be joined with the breakBefore value of | 
| -    // the first in-flow child, and breakAfter will be joined with the breakAfter value of the | 
| -    // last in-flow child. This is done in order to honor the requirement that a class A break | 
| -    // point [1] may only exists *between* in-flow siblings (i.e. not before the first child | 
| -    // and not after the last child). | 
| +    // Start with any applicable computed break-after and break-before values | 
| +    // for this object. During child layout, breakBefore will be joined with the | 
| +    // breakBefore value of the first in-flow child, and breakAfter will be | 
| +    // joined with the breakAfter value of the last in-flow child. This is done | 
| +    // in order to honor the requirement that a class A break point [1] may only | 
| +    // exists *between* in-flow siblings (i.e. not before the first child and | 
| +    // not after the last child). | 
| // | 
| // [1] https://drafts.csswg.org/css-break/#possible-breaks | 
| setBreakBefore(LayoutBlock::breakBefore()); | 
| @@ -529,9 +549,10 @@ inline bool LayoutBlockFlow::layoutBlockFlow(bool relayoutChildren, | 
| bool preferredLogicalWidthsBecameDirty = | 
| !preferredLogicalWidthsWereDirty && preferredLogicalWidthsDirty(); | 
| if (preferredLogicalWidthsBecameDirty) { | 
| -    // The only thing that should dirty preferred widths at this point is the addition of | 
| -    // overflow:auto scrollbars in a descendant.  To avoid a potential infinite loop, | 
| -    // run layout again with auto scrollbars frozen in their current state. | 
| +    // The only thing that should dirty preferred widths at this point is the | 
| +    // addition of overflow:auto scrollbars in a descendant. To avoid a | 
| +    // potential infinite loop, run layout again with auto scrollbars frozen in | 
| +    // their current state. | 
| PaintLayerScrollableArea::FreezeScrollbarsScope freezeScrollbars; | 
| return layoutBlockFlow(relayoutChildren, pageLogicalHeight, layoutScope); | 
| } | 
| @@ -565,7 +586,8 @@ inline bool LayoutBlockFlow::layoutBlockFlow(bool relayoutChildren, | 
| // One of our children's floats may have become an overhanging float for us. | 
| for (LayoutObject* child = lastChild(); child; | 
| child = child->previousSibling()) { | 
| -      // TODO(robhogan): We should exclude blocks that create formatting contexts, not just out of flow or floating blocks. | 
| +      // TODO(robhogan): We should exclude blocks that create formatting | 
| +      // contexts, not just out of flow or floating blocks. | 
| if (child->isLayoutBlockFlow() && | 
| !child->isFloatingOrOutOfFlowPositioned()) { | 
| LayoutBlockFlow* block = toLayoutBlockFlow(child); | 
| @@ -580,8 +602,10 @@ inline bool LayoutBlockFlow::layoutBlockFlow(bool relayoutChildren, | 
| addedOverhangingFloats = true; | 
| } | 
| } | 
| -    // If we have no overhanging floats we still pass a record of the lowest non-overhanging float up the tree so we can enclose it if | 
| -    // we are a formatting context and allow siblings to avoid it if they have negative margin and find themselves in its vicinity. | 
| +    // If we have no overhanging floats we still pass a record of the lowest | 
| +    // non-overhanging float up the tree so we can enclose it if we are a | 
| +    // formatting context and allow siblings to avoid it if they have negative | 
| +    // margin and find themselves in its vicinity. | 
| if (!addedOverhangingFloats) | 
| addLowestFloatFromChildren(lowestBlock); | 
| } | 
| @@ -595,7 +619,8 @@ inline bool LayoutBlockFlow::layoutBlockFlow(bool relayoutChildren, | 
| ? ForcedLayoutAfterContainingBlockMoved | 
| : DefaultLayout); | 
|  | 
| -  // Add overflow from children (unless we're multi-column, since in that case all our child overflow is clipped anyway). | 
| +  // Add overflow from children (unless we're multi-column, since in that case | 
| +  // all our child overflow is clipped anyway). | 
| computeOverflow(oldClientAfterEdge); | 
|  | 
| m_descendantsWithFloatsMarkedForLayout = false; | 
| @@ -641,10 +666,11 @@ void LayoutBlockFlow::determineLogicalLeftPositionForChild(LayoutBox& child) { | 
| startOffsetForLine(logicalTopForChild(child), DoNotIndentText, | 
| logicalHeightForChild(child)); | 
|  | 
| -    // If the child has an offset from the content edge to avoid floats then use that, otherwise let any negative | 
| -    // margin pull it back over the content edge or any positive margin push it out. | 
| -    // If the child is being centred then the margin calculated to do that has factored in any offset required to | 
| -    // avoid floats, so use it if necessary. | 
| +    // If the child has an offset from the content edge to avoid floats then use | 
| +    // that, otherwise let any negative margin pull it back over the content | 
| +    // edge or any positive margin push it out. | 
| +    // If the child is being centred then the margin calculated to do that has | 
| +    // factored in any offset required to avoid floats, so use it if necessary. | 
| if (style()->textAlign() == WEBKIT_CENTER || | 
| child.style()->marginStartUsing(style()).isAuto()) | 
| newPosition = | 
| @@ -681,21 +707,21 @@ void LayoutBlockFlow::markDescendantsWithFloatsForLayoutIfNeeded( | 
| LayoutBlockFlow& child, | 
| LayoutUnit newLogicalTop, | 
| LayoutUnit previousFloatLogicalBottom) { | 
| -  // TODO(mstensho): rework the code to return early when there is no need for marking, instead | 
| -  // of this |markDescendantsWithFloats| flag. | 
| +  // TODO(mstensho): rework the code to return early when there is no need for | 
| +  // marking, instead of this |markDescendantsWithFloats| flag. | 
| bool markDescendantsWithFloats = false; | 
| if (newLogicalTop != child.logicalTop() && !child.avoidsFloats() && | 
| child.containsFloats()) { | 
| markDescendantsWithFloats = true; | 
| } else if (UNLIKELY(newLogicalTop.mightBeSaturated())) { | 
| -    // The logical top might be saturated for very large elements. Comparing with the old | 
| -    // logical top might then yield a false negative, as adding and removing margins, borders | 
| -    // etc. from a saturated number might yield incorrect results. If this is the case, always | 
| -    // mark for layout. | 
| +    // The logical top might be saturated for very large elements. Comparing | 
| +    // with the old logical top might then yield a false negative, as adding and | 
| +    // removing margins, borders etc. from a saturated number might yield | 
| +    // incorrect results. If this is the case, always mark for layout. | 
| markDescendantsWithFloats = true; | 
| } else if (!child.avoidsFloats() || child.shrinkToAvoidFloats()) { | 
| -    // If an element might be affected by the presence of floats, then always mark it for | 
| -    // layout. | 
| +    // If an element might be affected by the presence of floats, then always | 
| +    // mark it for layout. | 
| if (std::max(previousFloatLogicalBottom, lowestFloatLogicalBottom()) > | 
| newLogicalTop) | 
| markDescendantsWithFloats = true; | 
| @@ -720,8 +746,9 @@ bool LayoutBlockFlow::positionAndLayoutOnceIfNeeded( | 
| markDescendantsWithFloatsForLayoutIfNeeded(childBlockFlow, newLogicalTop, | 
| previousFloatLogicalBottom); | 
|  | 
| -    // TODO(mstensho): A writing mode root is one thing, but we should be able to skip anything | 
| -    // that establishes a new block formatting context here. Their floats don't affect us. | 
| +    // TODO(mstensho): A writing mode root is one thing, but we should be able | 
| +    // to skip anything that establishes a new block formatting context here. | 
| +    // Their floats don't affect us. | 
| if (!childBlockFlow.isWritingModeRoot()) | 
| previousFloatLogicalBottom = | 
| std::max(previousFloatLogicalBottom, | 
| @@ -735,8 +762,9 @@ bool LayoutBlockFlow::positionAndLayoutOnceIfNeeded( | 
| SubtreeLayoutScope layoutScope(child); | 
| if (!child.needsLayout()) { | 
| if (newLogicalTop != oldLogicalTop && child.shrinkToAvoidFloats()) { | 
| -      // The child's width is affected by adjacent floats. When the child shifts to clear an | 
| -      // item, its width can change (because it has more available width). | 
| +      // The child's width is affected by adjacent floats. When the child shifts | 
| +      // to clear an item, its width can change (because it has more available | 
| +      // width). | 
| layoutScope.setChildNeedsLayout(&child); | 
| } else { | 
| markChildForPaginationRelayoutIfNeeded(child, layoutScope); | 
| @@ -753,15 +781,17 @@ void LayoutBlockFlow::insertForcedBreakBeforeChildIfNeeded( | 
| LayoutBox& child, | 
| BlockChildrenLayoutInfo& layoutInfo) { | 
| if (layoutInfo.isAtFirstInFlowChild()) { | 
| -    // There's no class A break point before the first child (only *between* siblings), so | 
| -    // steal its break value and join it with what we already have here. | 
| +    // There's no class A break point before the first child (only *between* | 
| +    // siblings), so steal its break value and join it with what we already have | 
| +    // here. | 
| setBreakBefore( | 
| joinFragmentainerBreakValues(breakBefore(), child.breakBefore())); | 
| return; | 
| } | 
|  | 
| -  // Figure out if a forced break should be inserted in front of the child. If we insert a forced | 
| -  // break, the margins on this child may not collapse with those preceding the break. | 
| +  // Figure out if a forced break should be inserted in front of the child. If | 
| +  // we insert a forced break, the margins on this child may not collapse with | 
| +  // those preceding the break. | 
| EBreak classABreakPointValue = | 
| child.classABreakPointValue(layoutInfo.previousBreakAfterValue()); | 
| if (isForcedFragmentainerBreakValue(classABreakPointValue)) { | 
| @@ -783,25 +813,28 @@ void LayoutBlockFlow::layoutBlockChild(LayoutBox& child, | 
| LayoutUnit oldPosMarginBefore = maxPositiveMarginBefore(); | 
| LayoutUnit oldNegMarginBefore = maxNegativeMarginBefore(); | 
|  | 
| -  // The child is a normal flow object. Compute the margins we will use for collapsing now. | 
| +  // The child is a normal flow object. Compute the margins we will use for | 
| +  // collapsing now. | 
| child.computeAndSetBlockDirectionMargins(this); | 
|  | 
| -  // Try to guess our correct logical top position. In most cases this guess will | 
| -  // be correct. Only if we're wrong (when we compute the real logical top position) | 
| -  // will we have to potentially relayout. | 
| +  // Try to guess our correct logical top position. In most cases this guess | 
| +  // will be correct. Only if we're wrong (when we compute the real logical top | 
| +  // position) will we have to potentially relayout. | 
| LayoutUnit estimateWithoutPagination; | 
| LayoutUnit logicalTopEstimate = | 
| estimateLogicalTopPosition(child, layoutInfo, estimateWithoutPagination); | 
|  | 
| -  // Cache our old rect so that we can dirty the proper paint invalidation rects if the child moves. | 
| +  // Cache our old rect so that we can dirty the proper paint invalidation rects | 
| +  // if the child moves. | 
| LayoutRect oldRect = child.frameRect(); | 
|  | 
| if (LayoutFlowThread* flowThread = flowThreadContainingBlock()) | 
| layoutInfo.storeMultiColumnLayoutState(*flowThread); | 
|  | 
| -  // Use the estimated block position and lay out the child if needed. After child layout, when | 
| -  // we have enough information to perform proper margin collapsing, float clearing and | 
| -  // pagination, we may have to reposition and lay out again if the estimate was wrong. | 
| +  // Use the estimated block position and lay out the child if needed. After | 
| +  // child layout, when we have enough information to perform proper margin | 
| +  // collapsing, float clearing and pagination, we may have to reposition and | 
| +  // lay out again if the estimate was wrong. | 
| bool childNeededLayout = | 
| positionAndLayoutOnceIfNeeded(child, logicalTopEstimate, layoutInfo); | 
|  | 
| @@ -812,13 +845,14 @@ void LayoutBlockFlow::layoutBlockChild(LayoutBox& child, | 
| bool childDiscardMarginAfter = mustDiscardMarginAfterForChild(child); | 
| bool paginated = view()->layoutState()->isPaginated(); | 
|  | 
| -  // If there should be a forced break before the child, we need to insert it before attempting | 
| -  // to collapse margins or apply clearance. | 
| +  // If there should be a forced break before the child, we need to insert it | 
| +  // before attempting to collapse margins or apply clearance. | 
| if (paginated) { | 
| -    // We will now insert the strut needed by any forced break. After this operation, we will | 
| -    // have calculated the offset where we can apply margin collapsing and clearance. After | 
| -    // having applied those things, we'll be at the position where we can honor requirements of | 
| -    // unbreakable content, which may extend the strut further. | 
| +    // We will now insert the strut needed by any forced break. After this | 
| +    // operation, we will have calculated the offset where we can apply margin | 
| +    // collapsing and clearance. After having applied those things, we'll be at | 
| +    // the position where we can honor requirements of unbreakable content, | 
| +    // which may extend the strut further. | 
| child.resetPaginationStrut(); | 
| insertForcedBreakBeforeChildIfNeeded(child, layoutInfo); | 
| } | 
| @@ -835,44 +869,50 @@ void LayoutBlockFlow::layoutBlockChild(LayoutBox& child, | 
| child, marginInfo, oldPosMarginBefore, oldNegMarginBefore, | 
| logicalTopBeforeClear, childIsSelfCollapsing, childDiscardMargin); | 
|  | 
| -  // If there's a forced break in front of this child, its final position has already been | 
| -  // determined. Otherwise, see if there are other reasons for breaking before it | 
| -  // (break-inside:avoid, or not enough space for the first piece of child content to fit in the | 
| -  // current fragmentainer), and adjust the position accordingly. | 
| +  // If there's a forced break in front of this child, its final position has | 
| +  // already been determined. Otherwise, see if there are other reasons for | 
| +  // breaking before it (break-inside:avoid, or not enough space for the first | 
| +  // piece of child content to fit in the current fragmentainer), and adjust the | 
| +  // position accordingly. | 
| if (paginated) { | 
| if (estimateWithoutPagination != newLogicalTop) { | 
| -      // We got a new position due to clearance or margin collapsing. Before we attempt to | 
| -      // paginate (which may result in the position changing again), let's try again at the | 
| -      // new position (since a new position may result in a new logical height). | 
| +      // We got a new position due to clearance or margin collapsing. Before we | 
| +      // attempt to paginate (which may result in the position changing again), | 
| +      // let's try again at the new position (since a new position may result in | 
| +      // a new logical height). | 
| positionAndLayoutOnceIfNeeded(child, newLogicalTop, layoutInfo); | 
| } | 
|  | 
| -    // We have now applied forced breaks, margin collapsing and clearance, and we're at the | 
| -    // position where we can honor requirements of unbreakable content. | 
| +    // We have now applied forced breaks, margin collapsing and clearance, and | 
| +    // we're at the position where we can honor requirements of unbreakable | 
| +    // content. | 
| newLogicalTop = adjustBlockChildForPagination( | 
| newLogicalTop, child, layoutInfo, | 
| atBeforeSideOfBlock && logicalTopBeforeClear == newLogicalTop); | 
| } | 
|  | 
| -  // Clearance, margin collapsing or pagination may have given us a new logical top, in which | 
| -  // case we may have to reposition and possibly relayout as well. If we determined during child | 
| -  // layout that we need to insert a break to honor widows, we also need to relayout. | 
| +  // Clearance, margin collapsing or pagination may have given us a new logical | 
| +  // top, in which case we may have to reposition and possibly relayout as well. | 
| +  // If we determined during child layout that we need to insert a break to | 
| +  // honor widows, we also need to relayout. | 
| if (newLogicalTop != logicalTopEstimate || child.needsLayout() || | 
| (paginated && childLayoutBlockFlow && | 
| childLayoutBlockFlow->shouldBreakAtLineToAvoidWidow())) { | 
| positionAndLayoutOnceIfNeeded(child, newLogicalTop, layoutInfo); | 
| } | 
|  | 
| -  // If we previously encountered a self-collapsing sibling of this child that had clearance then | 
| -  // we set this bit to ensure we would not collapse the child's margins, and those of any subsequent | 
| -  // self-collapsing siblings, with our parent. If this child is not self-collapsing then it can | 
| -  // collapse its margins with the parent so reset the bit. | 
| +  // If we previously encountered a self-collapsing sibling of this child that | 
| +  // had clearance then we set this bit to ensure we would not collapse the | 
| +  // child's margins, and those of any subsequent self-collapsing siblings, with | 
| +  // our parent. If this child is not self-collapsing then it can collapse its | 
| +  // margins with the parent so reset the bit. | 
| if (!marginInfo.canCollapseMarginAfterWithLastChild() && | 
| !childIsSelfCollapsing) | 
| marginInfo.setCanCollapseMarginAfterWithLastChild(true); | 
|  | 
| // We are no longer at the top of the block if we encounter a non-empty child. | 
| -  // This has to be done after checking for clear, so that margins can be reset if a clear occurred. | 
| +  // This has to be done after checking for clear, so that margins can be reset | 
| +  // if a clear occurred. | 
| if (marginInfo.atBeforeSideOfBlock() && !childIsSelfCollapsing) | 
| marginInfo.setAtBeforeSideOfBlock(false); | 
|  | 
| @@ -881,35 +921,40 @@ void LayoutBlockFlow::layoutBlockChild(LayoutBox& child, | 
|  | 
| LayoutSize childOffset = child.location() - oldRect.location(); | 
|  | 
| -  // Update our height now that the child has been placed in the correct position. | 
| +  // Update our height now that the child has been placed in the correct | 
| +  // position. | 
| setLogicalHeight(logicalHeight() + logicalHeightForChild(child)); | 
| if (mustSeparateMarginAfterForChild(child)) { | 
| setLogicalHeight(logicalHeight() + marginAfterForChild(child)); | 
| marginInfo.clearMargin(); | 
| } | 
| -  // If the child has overhanging floats that intrude into following siblings (or possibly out | 
| -  // of this block), then the parent gets notified of the floats now. | 
| +  // If the child has overhanging floats that intrude into following siblings | 
| +  // (or possibly out of this block), then the parent gets notified of the | 
| +  // floats now. | 
| if (childLayoutBlockFlow) | 
| addOverhangingFloats(childLayoutBlockFlow, !childNeededLayout); | 
|  | 
| -  // If the child moved, we have to invalidate its paint as well as any floating/positioned | 
| -  // descendants. An exception is if we need a layout. In this case, we know we're going to | 
| -  // invalidate our paint (and the child) anyway. | 
| +  // If the child moved, we have to invalidate its paint as well as any | 
| +  // floating/positioned descendants. An exception is if we need a layout. | 
| +  // In this case, we know we're going to invalidate our paint (and the child) | 
| +  // anyway. | 
| if (!selfNeedsLayout() && (childOffset.width() || childOffset.height()) && | 
| child.isLayoutBlockFlow()) | 
| BlockFlowPaintInvalidator(toLayoutBlockFlow(child)) | 
| .invalidatePaintForOverhangingFloats(); | 
|  | 
| if (paginated) { | 
| -    // Keep track of the break-after value of the child, so that it can be joined with the | 
| -    // break-before value of the next in-flow object at the next class A break point. | 
| +    // Keep track of the break-after value of the child, so that it can be | 
| +    // joined with the break-before value of the next in-flow object at the next | 
| +    // class A break point. | 
| layoutInfo.setPreviousBreakAfterValue(child.breakAfter()); | 
|  | 
| paginatedContentWasLaidOut(child.logicalBottom()); | 
| } | 
|  | 
| if (child.isLayoutMultiColumnSpannerPlaceholder()) { | 
| -    // The actual column-span:all element is positioned by this placeholder child. | 
| +    // The actual column-span:all element is positioned by this placeholder | 
| +    // child. | 
| positionSpannerDescendant(toLayoutMultiColumnSpannerPlaceholder(child)); | 
| } | 
| } | 
| @@ -922,49 +967,55 @@ LayoutUnit LayoutBlockFlow::adjustBlockChildForPagination( | 
| LayoutBlockFlow* childBlockFlow = | 
| child.isLayoutBlockFlow() ? toLayoutBlockFlow(&child) : 0; | 
|  | 
| -  // See if we need a soft (unforced) break in front of this child, and set the pagination strut | 
| -  // in that case. An unforced break may come from two sources: | 
| -  // 1. The first piece of content inside the child doesn't fit in the current page or column | 
| -  // 2. The child itself has breaking restrictions (break-inside:avoid, replaced content, etc.) | 
| -  // and doesn't fully fit in the current page or column. | 
| +  // See if we need a soft (unforced) break in front of this child, and set the | 
| +  // pagination strut in that case. An unforced break may come from two sources: | 
| +  // 1. The first piece of content inside the child doesn't fit in the current | 
| +  //    page or column | 
| +  // 2. The child itself has breaking restrictions (break-inside:avoid, replaced | 
| +  //    content, etc.) and doesn't fully fit in the current page or column. | 
| // | 
| -  // No matter which source, if we need to insert a strut, it should always take us to the exact | 
| -  // top of a page or column further ahead, or be zero. | 
| +  // No matter which source, if we need to insert a strut, it should always take | 
| +  // us to the exact top of a page or column further ahead, or be zero. | 
|  | 
| -  // The first piece of content inside the child may have set a strut during layout. Currently, | 
| -  // only block flows support strut propagation, but this may (and should) change in the future. | 
| -  // See crbug.com/539873 | 
| +  // The first piece of content inside the child may have set a strut during | 
| +  // layout. Currently, only block flows support strut propagation, but this may | 
| +  // (and should) change in the future. See crbug.com/539873 | 
| LayoutUnit strutFromContent = | 
| childBlockFlow ? childBlockFlow->paginationStrutPropagatedFromChild() | 
| : LayoutUnit(); | 
| LayoutUnit logicalTopWithContentStrut = logicalTop + strutFromContent; | 
|  | 
| -  // For replaced elements and scrolled elements, we want to shift them to the next page if they don't fit on the current one. | 
| +  // For replaced elements and scrolled elements, we want to shift them to the | 
| +  // next page if they don't fit on the current one. | 
| LayoutUnit logicalTopAfterUnsplittable = | 
| adjustForUnsplittableChild(child, logicalTop); | 
|  | 
| -  // Pick the largest offset. Tall unsplittable content may take us to a page or column further | 
| -  // ahead than the next one. | 
| +  // Pick the largest offset. Tall unsplittable content may take us to a page or | 
| +  // column further ahead than the next one. | 
| LayoutUnit logicalTopAfterPagination = | 
| std::max(logicalTopWithContentStrut, logicalTopAfterUnsplittable); | 
| LayoutUnit newLogicalTop = logicalTop; | 
|  | 
| -  // Forced breaks may already have caused a strut, and this needs to be added together with | 
| -  // any strut detected here in this method. | 
| +  // Forced breaks may already have caused a strut, and this needs to be added | 
| +  // together with any strut detected here in this method. | 
| LayoutUnit previousStrut = child.paginationStrut(); | 
|  | 
| if (LayoutUnit paginationStrut = | 
| logicalTopAfterPagination - logicalTop + previousStrut) { | 
| ASSERT(paginationStrut > 0); | 
| -    // If we're not at the first in-flow child, there's a class A break point before the child. If we *are* at the | 
| -    // first in-flow child, but the child isn't flush with the content edge of its container, due to e.g. clearance, | 
| -    // there's a class C break point before the child. Otherwise we should propagate the strut to our parent block, | 
| -    // and attempt to break there instead. See https://drafts.csswg.org/css-break/#possible-breaks | 
| +    // If we're not at the first in-flow child, there's a class A break point | 
| +    // before the child. If we *are* at the first in-flow child, but the child | 
| +    // isn't flush with the content edge of its container, due to e.g. | 
| +    // clearance, there's a class C break point before the child. Otherwise we | 
| +    // should propagate the strut to our parent block, and attempt to break | 
| +    // there instead. See https://drafts.csswg.org/css-break/#possible-breaks | 
| if (layoutInfo.isAtFirstInFlowChild() && atBeforeSideOfBlock && | 
| allowsPaginationStrut()) { | 
| -      // FIXME: Should really check if we're exceeding the page height before propagating the strut, but we don't | 
| -      // have all the information to do so (the strut only has the remaining amount to push). Gecko gets this wrong too | 
| -      // and pushes to the next page anyway, so not too concerned about it. | 
| +      // FIXME: Should really check if we're exceeding the page height before | 
| +      // propagating the strut, but we don't have all the information to do so | 
| +      // (the strut only has the remaining amount to push). Gecko gets this | 
| +      // wrong too and pushes to the next page anyway, so not too concerned | 
| +      // about it. | 
| paginationStrut += logicalTop + marginBeforeIfFloating(); | 
| setPaginationStrutPropagatedFromChild(paginationStrut); | 
| child.resetPaginationStrut(); | 
| @@ -972,12 +1023,14 @@ LayoutUnit LayoutBlockFlow::adjustBlockChildForPagination( | 
| childBlockFlow->setPaginationStrutPropagatedFromChild(LayoutUnit()); | 
| } else { | 
| child.setPaginationStrut(paginationStrut); | 
| -      // |previousStrut| was already baked into the logical top, so don't add it again. | 
| +      // |previousStrut| was already baked into the logical top, so don't add it | 
| +      // again. | 
| newLogicalTop += paginationStrut - previousStrut; | 
| } | 
| } | 
|  | 
| -  // Similar to how we apply clearance. Go ahead and boost height() to be the place where we're going to position the child. | 
| +  // Similar to how we apply clearance. Go ahead and boost height() to be the | 
| +  // place where we're going to position the child. | 
| setLogicalHeight(logicalHeight() + (newLogicalTop - logicalTop)); | 
|  | 
| // Return the final adjusted logical top. | 
| @@ -990,13 +1043,14 @@ static bool shouldSetStrutOnBlock(const LayoutBlockFlow& block, | 
| int lineIndex, | 
| LayoutUnit pageLogicalHeight) { | 
| if (lineBox == block.firstRootBox()) { | 
| -    // This is the first line in the block. We can take the whole block with us to the next page | 
| -    // or column, rather than keeping a content-less portion of it in the previous one. Only do | 
| -    // this if the line is flush with the content edge of the block, though. If it isn't, it | 
| -    // means that the line was pushed downwards by preceding floats that didn't fit beside the | 
| -    // line, and we don't want to move all that, since it has already been established that it | 
| -    // fits nicely where it is. In this case we have a class "C" break point [1] in front of | 
| -    // this line. | 
| +    // This is the first line in the block. We can take the whole block with us | 
| +    // to the next page or column, rather than keeping a content-less portion of | 
| +    // it in the previous one. Only do this if the line is flush with the | 
| +    // content edge of the block, though. If it isn't, it means that the line | 
| +    // was pushed downwards by preceding floats that didn't fit beside the line, | 
| +    // and we don't want to move all that, since it has already been established | 
| +    // that it fits nicely where it is. In this case we have a class "C" break | 
| +    // point [1] in front of this line. | 
| // | 
| // [1] https://drafts.csswg.org/css-break/#possible-breaks | 
| if (lineLogicalOffset > block.borderAndPaddingBefore()) | 
| @@ -1006,35 +1060,39 @@ static bool shouldSetStrutOnBlock(const LayoutBlockFlow& block, | 
| lineBox.lineBottomWithLeading() - lineBox.lineTopWithLeading(); | 
| LayoutUnit totalLogicalHeight = | 
| lineHeight + lineLogicalOffset.clampNegativeToZero(); | 
| -    // It's rather pointless to break before the block if the current line isn't going to | 
| -    // fit in the same column or page, so check that as well. | 
| +    // It's rather pointless to break before the block if the current line isn't | 
| +    // going to fit in the same column or page, so check that as well. | 
| if (totalLogicalHeight > pageLogicalHeight) | 
| return false; | 
| } else { | 
| if (lineIndex > block.style()->orphans()) | 
| return false; | 
|  | 
| -    // Not enough orphans here. Push the entire block to the next column / page as an attempt to | 
| -    // better satisfy the orphans requirement. | 
| +    // Not enough orphans here. Push the entire block to the next column / page | 
| +    // as an attempt to better satisfy the orphans requirement. | 
| // | 
| -    // Note that we should ideally check if the first line in the block is flush with the | 
| -    // content edge of the block here, because if it isn't, we should break at the class "C" | 
| -    // break point in front of the first line, rather than before the entire block. | 
| +    // Note that we should ideally check if the first line in the block is flush | 
| +    // with the content edge of the block here, because if it isn't, we should | 
| +    // break at the class "C" break point in front of the first line, rather | 
| +    // than before the entire block. | 
| } | 
| return block.allowsPaginationStrut(); | 
| } | 
|  | 
| void LayoutBlockFlow::adjustLinePositionForPagination(RootInlineBox& lineBox, | 
| LayoutUnit& delta) { | 
| -  // TODO(mstensho): Pay attention to line overflow. It should be painted in the same column as | 
| -  // the rest of the line, possibly overflowing the column. We currently only allow overflow above | 
| -  // the first column. We clip at all other column boundaries, and that's how it has to be for | 
| -  // now. The paint we have to do when a column has overflow has to be special. We need to exclude | 
| -  // content that paints in a previous column (and content that paints in the following column). | 
| +  // TODO(mstensho): Pay attention to line overflow. It should be painted in the | 
| +  // same column as the rest of the line, possibly overflowing the column. We | 
| +  // currently only allow overflow above the first column. We clip at all other | 
| +  // column boundaries, and that's how it has to be for now. The paint we have | 
| +  // to do when a column has overflow has to be special. | 
| +  // We need to exclude content that paints in a previous column (and content | 
| +  // that paints in the following column). | 
| // | 
| -  // FIXME: Another problem with simply moving lines is that the available line width may change (because of floats). | 
| -  // Technically if the location we move the line to has a different line width than our old position, then we need to dirty the | 
| -  // line and all following lines. | 
| +  // FIXME: Another problem with simply moving lines is that the available line | 
| +  // width may change (because of floats). Technically if the location we move | 
| +  // the line to has a different line width than our old position, then we need | 
| +  // to dirty the line and all following lines. | 
| LayoutUnit logicalOffset = lineBox.lineTopWithLeading(); | 
| LayoutUnit lineHeight = lineBox.lineBottomWithLeading() - logicalOffset; | 
| logicalOffset += delta; | 
| @@ -1052,20 +1110,23 @@ void LayoutBlockFlow::adjustLinePositionForPagination(RootInlineBox& lineBox, | 
| LayoutUnit paginationStrut = calculatePaginationStrutToFitContent( | 
| logicalOffset, remainingLogicalHeight, lineHeight); | 
| LayoutUnit newLogicalOffset = logicalOffset + paginationStrut; | 
| -    // Moving to a different page or column may mean that its height is different. | 
| +    // Moving to a different page or column may mean that its height is | 
| +    // different. | 
| pageLogicalHeight = pageLogicalHeightForOffset(newLogicalOffset); | 
| if (lineHeight > pageLogicalHeight) { | 
| -      // Too tall to fit in one page / column. Give up. Don't push to the next page / column. | 
| -      // TODO(mstensho): Get rid of this. This is just utter weirdness, but the other browsers | 
| -      // also do something slightly similar, although in much more specific cases than we do here, | 
| -      // and printing Google Docs depends on it. | 
| +      // Too tall to fit in one page / column. Give up. Don't push to the next | 
| +      // page / column. | 
| +      // TODO(mstensho): Get rid of this. This is just utter weirdness, but the | 
| +      // other browsers also do something slightly similar, although in much | 
| +      // more specific cases than we do here, and printing Google Docs depends | 
| +      // on it. | 
| paginatedContentWasLaidOut(logicalOffset + lineHeight); | 
| return; | 
| } | 
|  | 
| -    // We need to insert a break now, either because there's no room for the line in the | 
| -    // current column / page, or because we have determined that we need a break to satisfy | 
| -    // widow requirements. | 
| +    // We need to insert a break now, either because there's no room for the | 
| +    // line in the current column / page, or because we have determined that we | 
| +    // need a break to satisfy widow requirements. | 
| if (shouldBreakAtLineToAvoidWidow() && | 
| lineBreakToAvoidWidow() == lineIndex) { | 
| clearShouldBreakAtLineToAvoidWidow(); | 
| @@ -1073,11 +1134,12 @@ void LayoutBlockFlow::adjustLinePositionForPagination(RootInlineBox& lineBox, | 
| } | 
| if (shouldSetStrutOnBlock(*this, lineBox, logicalOffset, lineIndex, | 
| pageLogicalHeight)) { | 
| -      // Note that when setting the strut on a block, it may be propagated to parent blocks | 
| -      // later on, if a block's logical top is flush with that of its parent. We don't want | 
| -      // content-less portions (struts) at the beginning of a block before a break, if it can | 
| -      // be avoided. After all, that's the reason for setting struts on blocks and not lines | 
| -      // in the first place. | 
| +      // Note that when setting the strut on a block, it may be propagated to | 
| +      // parent blocks later on, if a block's logical top is flush with that of | 
| +      // its parent. We don't want content-less portions (struts) at the | 
| +      // beginning of a block before a break, if it can be avoided. After all, | 
| +      // that's the reason for setting struts on blocks and not lines in the | 
| +      // first place. | 
| LayoutUnit strut = | 
| paginationStrut + logicalOffset + marginBeforeIfFloating(); | 
| setPaginationStrutPropagatedFromChild(strut); | 
| @@ -1095,34 +1157,37 @@ void LayoutBlockFlow::adjustLinePositionForPagination(RootInlineBox& lineBox, | 
| // We're at the very top of a page or column. | 
| if (lineBox != firstRootBox()) | 
| lineBox.setIsFirstAfterPageBreak(true); | 
| -    // If this is the first line in the block, and the block has a top border, padding, or (in | 
| -    // case it's a float) margin, we may want to set a strut on the block, so that everything | 
| -    // ends up in the next column or page. Setting a strut on the block is also important when | 
| -    // it comes to satisfying orphan requirements. | 
| +    // If this is the first line in the block, and the block has a top border, | 
| +    // padding, or (in case it's a float) margin, we may want to set a strut on | 
| +    // the block, so that everything ends up in the next column or page. Setting | 
| +    // a strut on the block is also important when it comes to satisfying orphan | 
| +    // requirements. | 
| if (shouldSetStrutOnBlock(*this, lineBox, logicalOffset, lineIndex, | 
| pageLogicalHeight)) | 
| strutToPropagate = logicalOffset + marginBeforeIfFloating(); | 
| } else if (lineBox == firstRootBox() && allowsPaginationStrut()) { | 
| -    // This is the first line in the block. The block may still start in the previous column or | 
| -    // page, and if that's the case, attempt to pull it over to where this line is, so that we | 
| -    // don't split the top border, padding, or (in case it's a float) margin. | 
| +    // This is the first line in the block. The block may still start in the | 
| +    // previous column or page, and if that's the case, attempt to pull it over | 
| +    // to where this line is, so that we don't split the top border, padding, or | 
| +    // (in case it's a float) margin. | 
| LayoutUnit totalLogicalOffset = logicalOffset + marginBeforeIfFloating(); | 
| LayoutUnit strut = | 
| remainingLogicalHeight + totalLogicalOffset - pageLogicalHeight; | 
| if (strut > 0) { | 
| -      // The block starts in a previous column or page. Set a strut on the block if there's | 
| -      // room for the top border, padding and (if it's a float) margin and the line in one | 
| -      // column or page. | 
| +      // The block starts in a previous column or page. Set a strut on the block | 
| +      // if there's room for the top border, padding and (if it's a float) | 
| +      // margin and the line in one column or page. | 
| if (totalLogicalOffset + lineHeight <= pageLogicalHeight) | 
| strutToPropagate = strut; | 
| } | 
| } | 
|  | 
| -  // If we found that some preceding content (lines, border and padding) belongs together with | 
| -  // this line, we should pull the entire block with us to the fragmentainer we're currently | 
| -  // in. We need to avoid this when the block precedes the first fragmentainer, though. We | 
| -  // shouldn't fragment content there, but rather let it appear in the overflow area before the | 
| -  // first fragmentainer. | 
| +  // If we found that some preceding content (lines, border and padding) belongs | 
| +  // together with this line, we should pull the entire block with us to the | 
| +  // fragmentainer we're currently in. We need to avoid this when the block | 
| +  // precedes the first fragmentainer, though. We shouldn't fragment content | 
| +  // there, but rather let it appear in the overflow area before the first | 
| +  // fragmentainer. | 
| if (strutToPropagate && offsetFromLogicalTopOfFirstPage() > LayoutUnit()) | 
| setPaginationStrutPropagatedFromChild(strutToPropagate); | 
|  | 
| @@ -1150,8 +1215,8 @@ LayoutUnit LayoutBlockFlow::adjustForUnsplittableChild( | 
| logicalOffset, remainingLogicalHeight, childLogicalHeight); | 
| if (paginationStrut == remainingLogicalHeight && | 
| remainingLogicalHeight == pageLogicalHeight) { | 
| -    // Don't break if we were at the top of a page, and we failed to fit the content | 
| -    // completely. No point in leaving a page completely blank. | 
| +    // Don't break if we were at the top of a page, and we failed to fit the | 
| +    // content completely. No point in leaving a page completely blank. | 
| return logicalOffset; | 
| } | 
| return logicalOffset + paginationStrut; | 
| @@ -1174,7 +1239,8 @@ void LayoutBlockFlow::rebuildFloatsFromIntruding() { | 
| } | 
| } | 
|  | 
| -  // Inline blocks are covered by the isAtomicInlineLevel() check in the avoidFloats method. | 
| +  // Inline blocks are covered by the isAtomicInlineLevel() check in the | 
| +  // avoidFloats method. | 
| if (avoidsFloats() || isDocumentElement() || isLayoutView() || | 
| isFloatingOrOutOfFlowPositioned() || isTableCell()) { | 
| if (m_floatingObjects) { | 
| @@ -1194,15 +1260,18 @@ void LayoutBlockFlow::rebuildFloatsFromIntruding() { | 
| m_floatingObjects->clear(); | 
| } | 
|  | 
| -  // We should not process floats if the parent node is not a LayoutBlockFlow. Otherwise, we will add | 
| -  // floats in an invalid context. This will cause a crash arising from a bad cast on the parent. | 
| -  // See <rdar://problem/8049753>, where float property is applied on a text node in a SVG. | 
| +  // We should not process floats if the parent node is not a LayoutBlockFlow. | 
| +  // Otherwise, we will add floats in an invalid context. This will cause a | 
| +  // crash arising from a bad cast on the parent. | 
| +  // See <rdar://problem/8049753>, where float property is applied on a text | 
| +  // node in a SVG. | 
| if (!parent() || !parent()->isLayoutBlockFlow()) | 
| return; | 
|  | 
| -  // Attempt to locate a previous sibling with overhanging floats. We skip any elements that | 
| -  // may have shifted to avoid floats, and any objects whose floats cannot interact with objects | 
| -  // outside it (i.e. objects that create a new block formatting context). | 
| +  // Attempt to locate a previous sibling with overhanging floats. We skip any | 
| +  // elements that may have shifted to avoid floats, and any objects whose | 
| +  // floats cannot interact with objects outside it (i.e. objects that create a | 
| +  // new block formatting context). | 
| LayoutBlockFlow* parentBlockFlow = toLayoutBlockFlow(parent()); | 
| bool siblingFloatMayIntrude = false; | 
| LayoutObject* prev = previousSibling(); | 
| @@ -1214,9 +1283,11 @@ void LayoutBlockFlow::rebuildFloatsFromIntruding() { | 
| prev = prev->previousSibling(); | 
| } | 
|  | 
| -  // First add in floats from the parent. Self-collapsing blocks let their parent track any floats that intrude into | 
| -  // them (as opposed to floats they contain themselves) so check for those here too. If margin collapsing has moved | 
| -  // us up past the top a previous sibling then we need to check for floats from the parent too. | 
| +  // First add in floats from the parent. Self-collapsing blocks let their | 
| +  // parent track any floats that intrude into them (as opposed to floats they | 
| +  // contain themselves) so check for those here too. If margin collapsing has | 
| +  // moved us up past the top a previous sibling then we need to check for | 
| +  // floats from the parent too. | 
| bool parentFloatsMayIntrude = | 
| !siblingFloatMayIntrude && | 
| (!prev || toLayoutBlockFlow(prev)->isSelfCollapsingBlock() || | 
| @@ -1227,7 +1298,8 @@ void LayoutBlockFlow::rebuildFloatsFromIntruding() { | 
| parentBlockFlow->logicalLeftOffsetForContent(), | 
| logicalTop()); | 
|  | 
| -  // Add overhanging floats from the previous LayoutBlockFlow, but only if it has a float that intrudes into our space. | 
| +  // Add overhanging floats from the previous LayoutBlockFlow, but only if it | 
| +  // has a float that intrudes into our space. | 
| if (prev) { | 
| LayoutBlockFlow* previousBlockFlow = toLayoutBlockFlow(prev); | 
| if (logicalTop() < previousBlockFlow->logicalTop() + | 
| @@ -1304,8 +1376,9 @@ void LayoutBlockFlow::rebuildFloatsFromIntruding() { | 
|  | 
| markLinesDirtyInBlockRange(changeLogicalTop, changeLogicalBottom); | 
| } else if (!oldIntrudingFloatSet.isEmpty()) { | 
| -    // If there are previously intruding floats that no longer intrude, then children with floats | 
| -    // should also get layout because they might need their floating object lists cleared. | 
| +    // If there are previously intruding floats that no longer intrude, then | 
| +    // children with floats should also get layout because they might need their | 
| +    // floating object lists cleared. | 
| if (m_floatingObjects->set().size() < oldIntrudingFloatSet.size()) { | 
| markAllDescendantsWithFloatsForLayout(); | 
| } else { | 
| @@ -1349,7 +1422,8 @@ void LayoutBlockFlow::layoutBlockChildren(bool relayoutChildren, | 
| child->setMayNeedPaintInvalidation(); | 
|  | 
| if (childToExclude == child) | 
| -      continue;  // Skip this child, since it will be positioned by the specialized subclass (ruby runs). | 
| +      continue;  // Skip this child, since it will be positioned by the | 
| +                 // specialized subclass (ruby runs). | 
|  | 
| updateBlockChildDirtyBitsBeforeLayout(relayoutChildren, *child); | 
|  | 
| @@ -1364,11 +1438,12 @@ void LayoutBlockFlow::layoutBlockChildren(bool relayoutChildren, | 
| continue; | 
| } | 
| if (child->isColumnSpanAll()) { | 
| -      // This is not the containing block of the spanner. The spanner's placeholder will lay | 
| -      // it out in due course. For now we just need to consult our flow thread, so that the | 
| -      // columns (if any) preceding and following the spanner are laid out correctly. But | 
| -      // first we apply the pending margin, so that it's taken into consideration and doesn't | 
| -      // end up on the other side of the spanner. | 
| +      // This is not the containing block of the spanner. The spanner's | 
| +      // placeholder will lay it out in due course. For now we just need to | 
| +      // consult our flow thread, so that the columns (if any) preceding and | 
| +      // following the spanner are laid out correctly. But first we apply the | 
| +      // pending margin, so that it's taken into consideration and doesn't end | 
| +      // up on the other side of the spanner. | 
| setLogicalHeight(logicalHeight() + marginInfo.margin()); | 
| marginInfo.clearMargin(); | 
|  | 
| @@ -1383,8 +1458,9 @@ void LayoutBlockFlow::layoutBlockChildren(bool relayoutChildren, | 
| lastNormalFlowChild = child; | 
| } | 
|  | 
| -  // Now do the handling of the bottom of the block, adding in our bottom border/padding and | 
| -  // determining the correct collapsed bottom margin information. | 
| +  // Now do the handling of the bottom of the block, adding in our bottom | 
| +  // border/padding and determining the correct collapsed bottom margin | 
| +  // information. | 
| handleAfterSideOfBlock(lastNormalFlowChild, beforeEdge, afterEdge, | 
| marginInfo); | 
| } | 
| @@ -1411,10 +1487,11 @@ MarginInfo::MarginInfo(LayoutBlockFlow* blockFlow, | 
| m_canCollapseWithChildren && !beforeBorderPadding && | 
| blockStyle.marginBeforeCollapse() != MarginCollapseSeparate; | 
|  | 
| -  // If any height other than auto is specified in CSS, then we don't collapse our bottom | 
| -  // margins with our children's margins. To do otherwise would be to risk odd visual | 
| -  // effects when the children overflow out of the parent block and yet still collapse | 
| -  // with it. We also don't collapse if we have any bottom border/padding. | 
| +  // If any height other than auto is specified in CSS, then we don't collapse | 
| +  // our bottom margins with our children's margins. To do otherwise would be to | 
| +  // risk odd visual effects when the children overflow out of the parent block | 
| +  // and yet still collapse with it. We also don't collapse if we have any | 
| +  // bottom border/padding. | 
| m_canCollapseMarginAfterWithChildren = | 
| m_canCollapseWithChildren && !afterBorderPadding && | 
| (blockStyle.logicalHeight().isAuto() && | 
| @@ -1449,8 +1526,8 @@ LayoutBlockFlow::MarginValues LayoutBlockFlow::marginValuesForChild( | 
| LayoutBlockFlow* childLayoutBlockFlow = | 
| child.isLayoutBlockFlow() ? toLayoutBlockFlow(&child) : 0; | 
|  | 
| -  // If the child has the same directionality as we do, then we can just return its | 
| -  // margins in the same direction. | 
| +  // If the child has the same directionality as we do, then we can just return | 
| +  // its margins in the same direction. | 
| if (!child.isWritingModeRoot()) { | 
| if (childLayoutBlockFlow) { | 
| childBeforePositive = childLayoutBlockFlow->maxPositiveMarginBefore(); | 
| @@ -1462,8 +1539,9 @@ LayoutBlockFlow::MarginValues LayoutBlockFlow::marginValuesForChild( | 
| afterMargin = child.marginAfter(); | 
| } | 
| } else if (child.isHorizontalWritingMode() == isHorizontalWritingMode()) { | 
| -    // The child has a different directionality. If the child is parallel, then it's just | 
| -    // flipped relative to us. We can use the margins for the opposite edges. | 
| +    // The child has a different directionality. If the child is parallel, then | 
| +    // it's just flipped relative to us. We can use the margins for the opposite | 
| +    // edges. | 
| if (childLayoutBlockFlow) { | 
| childBeforePositive = childLayoutBlockFlow->maxPositiveMarginAfter(); | 
| childBeforeNegative = childLayoutBlockFlow->maxNegativeMarginAfter(); | 
| @@ -1474,8 +1552,9 @@ LayoutBlockFlow::MarginValues LayoutBlockFlow::marginValuesForChild( | 
| afterMargin = child.marginBefore(); | 
| } | 
| } else { | 
| -    // The child is perpendicular to us, which means its margins don't collapse but are on the | 
| -    // "logical left/right" sides of the child box. We can just return the raw margin in this case. | 
| +    // The child is perpendicular to us, which means its margins don't collapse | 
| +    // but are on the "logical left/right" sides of the child box. We can just | 
| +    // return the raw margin in this case. | 
| beforeMargin = marginBeforeForChild(child); | 
| afterMargin = marginAfterForChild(child); | 
| } | 
| @@ -1503,7 +1582,8 @@ LayoutUnit LayoutBlockFlow::collapseMargins(LayoutBox& child, | 
| bool childIsSelfCollapsing, | 
| bool childDiscardMarginBefore, | 
| bool childDiscardMarginAfter) { | 
| -  // The child discards the before margin when the the after margin has discard in the case of a self collapsing block. | 
| +  // The child discards the before margin when the the after margin has discard | 
| +  // in the case of a self collapsing block. | 
| childDiscardMarginBefore = childDiscardMarginBefore || | 
| (childDiscardMarginAfter && childIsSelfCollapsing); | 
|  | 
| @@ -1556,12 +1636,14 @@ LayoutUnit LayoutBlockFlow::collapseMargins(LayoutBox& child, | 
| setHasMarginBeforeQuirk(true); | 
| } | 
| } else { | 
| -      // The before margin of the container will also discard all the margins it is collapsing with. | 
| +      // The before margin of the container will also discard all the margins it | 
| +      // is collapsing with. | 
| setMustDiscardMarginBefore(); | 
| } | 
| } | 
|  | 
| -  // Once we find a child with discardMarginBefore all the margins collapsing with us must also discard. | 
| +  // Once we find a child with discardMarginBefore all the margins collapsing | 
| +  // with us must also discard. | 
| if (childDiscardMarginBefore) { | 
| marginInfo.setDiscardMargin(true); | 
| marginInfo.clearMargin(); | 
| @@ -1580,9 +1662,13 @@ LayoutUnit LayoutBlockFlow::collapseMargins(LayoutBox& child, | 
| !prev->isFloatingOrOutOfFlowPositioned() | 
| ? toLayoutBlockFlow(prev) | 
| : 0; | 
| -  // If the child's previous sibling is a self-collapsing block that cleared a float then its top border edge has been set at the bottom border edge | 
| -  // of the float. Since we want to collapse the child's top margin with the self-collapsing block's top and bottom margins we need to adjust our parent's height to match the | 
| -  // margin top of the self-collapsing block. If the resulting collapsed margin leaves the child still intruding into the float then we will want to clear it. | 
| +  // If the child's previous sibling is a self-collapsing block that cleared a | 
| +  // float then its top border edge has been set at the bottom border edge of | 
| +  // the float. Since we want to collapse the child's top margin with the self- | 
| +  // collapsing block's top and bottom margins we need to adjust our parent's | 
| +  // height to match the margin top of the self-collapsing block. If the | 
| +  // resulting collapsed margin leaves the child still intruding into the float | 
| +  // then we will want to clear it. | 
| if (!marginInfo.canCollapseWithMarginBefore() && previousBlockFlow && | 
| marginInfo.lastChildIsSelfCollapsingBlockWithClearance()) | 
| setLogicalHeight( | 
| @@ -1590,8 +1676,10 @@ LayoutUnit LayoutBlockFlow::collapseMargins(LayoutBox& child, | 
| marginValuesForChild(*previousBlockFlow).positiveMarginBefore()); | 
|  | 
| if (childIsSelfCollapsing) { | 
| -    // For a self collapsing block both the before and after margins get discarded. The block doesn't contribute anything to the height of the block. | 
| -    // Also, the child's top position equals the logical height of the container. | 
| +    // For a self collapsing block both the before and after margins get | 
| +    // discarded. The block doesn't contribute anything to the height of the | 
| +    // block. Also, the child's top position equals the logical height of the | 
| +    // container. | 
| if (!childDiscardMarginBefore && !marginInfo.discardMargin()) { | 
| // This child has no height. We need to compute our | 
| // position before we collapse the child's margins together, | 
| @@ -1619,9 +1707,9 @@ LayoutUnit LayoutBlockFlow::collapseMargins(LayoutBox& child, | 
| if (mustSeparateMarginBeforeForChild(child)) { | 
| ASSERT(!marginInfo.discardMargin() || | 
| (marginInfo.discardMargin() && !marginInfo.margin())); | 
| -      // If we are at the before side of the block and we collapse, ignore the computed margin | 
| -      // and just add the child margin to the container height. This will correctly position | 
| -      // the child inside the container. | 
| +      // If we are at the before side of the block and we collapse, ignore the | 
| +      // computed margin and just add the child margin to the container height. | 
| +      // This will correctly position the child inside the container. | 
| LayoutUnit separateMargin = !marginInfo.canCollapseWithMarginBefore() | 
| ? marginInfo.margin() | 
| : LayoutUnit(); | 
| @@ -1654,8 +1742,8 @@ LayoutUnit LayoutBlockFlow::collapseMargins(LayoutBox& child, | 
| marginInfo.setHasMarginAfterQuirk(hasMarginAfterQuirk(&child)); | 
| } | 
|  | 
| -  // If margins would pull us past the top of the next page, then we need to pull back and pretend like the margins | 
| -  // collapsed into the page edge. | 
| +  // If margins would pull us past the top of the next page, then we need to | 
| +  // pull back and pretend like the margins collapsed into the page edge. | 
| LayoutState* layoutState = view()->layoutState(); | 
| if (layoutState->isPaginated() && | 
| isPageLogicalHeightKnown(beforeCollapseLogicalTop) && | 
| @@ -1667,8 +1755,9 @@ LayoutUnit LayoutBlockFlow::collapseMargins(LayoutBox& child, | 
| } | 
|  | 
| if (previousBlockFlow) { | 
| -    // If |child| is a self-collapsing block it may have collapsed into a previous sibling and although it hasn't reduced the height of the parent yet | 
| -    // any floats from the parent will now overhang. | 
| +    // If |child| is a self-collapsing block it may have collapsed into a | 
| +    // previous sibling and although it hasn't reduced the height of the parent | 
| +    // yet any floats from the parent will now overhang. | 
| LayoutUnit oldLogicalHeight = logicalHeight(); | 
| setLogicalHeight(logicalTop); | 
| if (!previousBlockFlow->avoidsFloats() && | 
| @@ -1677,9 +1766,11 @@ LayoutUnit LayoutBlockFlow::collapseMargins(LayoutBox& child, | 
| addOverhangingFloats(previousBlockFlow, false); | 
| setLogicalHeight(oldLogicalHeight); | 
|  | 
| -    // If |child|'s previous sibling is or contains a self-collapsing block that cleared a float and margin collapsing resulted in |child| moving up | 
| -    // into the margin area of the self-collapsing block then the float it clears is now intruding into |child|. Layout again so that we can look for | 
| -    // floats in the parent that overhang |child|'s new logical top. | 
| +    // If |child|'s previous sibling is or contains a self-collapsing block that | 
| +    // cleared a float and margin collapsing resulted in |child| moving up | 
| +    // into the margin area of the self-collapsing block then the float it | 
| +    // clears is now intruding into |child|. Layout again so that we can look | 
| +    // for floats in the parent that overhang |child|'s new logical top. | 
| bool logicalTopIntrudesIntoFloat = logicalTop < beforeCollapseLogicalTop; | 
| if (logicalTopIntrudesIntoFloat && containsFloats() && | 
| !child.avoidsFloats() && lowestFloatLogicalBottom() > logicalTop) | 
| @@ -1695,8 +1786,9 @@ void LayoutBlockFlow::adjustPositionedBlock( | 
| const BlockChildrenLayoutInfo& layoutInfo) { | 
| LayoutUnit logicalTop = logicalHeight(); | 
|  | 
| -  // Forced breaks are only specified on in-flow objects, but auto-positioned out-of-flow objects | 
| -  // may be affected by a break-after value of the previous in-flow object. | 
| +  // Forced breaks are only specified on in-flow objects, but auto-positioned | 
| +  // out-of-flow objects may be affected by a break-after value of the previous | 
| +  // in-flow object. | 
| if (view()->layoutState()->isPaginated()) | 
| logicalTop = | 
| applyForcedBreak(logicalTop, layoutInfo.previousBreakAfterValue()); | 
| @@ -1706,7 +1798,8 @@ void LayoutBlockFlow::adjustPositionedBlock( | 
| const MarginInfo& marginInfo = layoutInfo.marginInfo(); | 
| if (!marginInfo.canCollapseWithMarginBefore()) { | 
| // Positioned blocks don't collapse margins, so add the margin provided by | 
| -    // the container now. The child's own margin is added later when calculating its logical top. | 
| +    // the container now. The child's own margin is added later when calculating | 
| +    // its logical top. | 
| LayoutUnit collapsedBeforePos = marginInfo.positiveMargin(); | 
| LayoutUnit collapsedBeforeNeg = marginInfo.negativeMargin(); | 
| logicalTop += collapsedBeforePos - collapsedBeforeNeg; | 
| @@ -1737,7 +1830,8 @@ LayoutUnit LayoutBlockFlow::clearFloatsIfNeeded(LayoutBox& child, | 
| // For self-collapsing blocks that clear, they can still collapse their | 
| // margins with following siblings. Reset the current margins to represent | 
| // the self-collapsing block's margins only. | 
| -    // If DISCARD is specified for -webkit-margin-collapse, reset the margin values. | 
| +    // If DISCARD is specified for -webkit-margin-collapse, reset the margin | 
| +    // values. | 
| LayoutBlockFlow::MarginValues childMargins = marginValuesForChild(child); | 
| if (!childDiscardMargin) { | 
| marginInfo.setPositiveMargin( | 
| @@ -1751,18 +1845,28 @@ LayoutUnit LayoutBlockFlow::clearFloatsIfNeeded(LayoutBox& child, | 
| } | 
|  | 
| // CSS2.1 states: | 
| -    // "If the top and bottom margins of an element with clearance are adjoining, its margins collapse with | 
| -    // the adjoining margins of following siblings but that resulting margin does not collapse with the bottom margin of the parent block." | 
| -    // So the parent's bottom margin cannot collapse through this block or any subsequent self-collapsing blocks. Set a bit to ensure | 
| -    // this happens; it will get reset if we encounter an in-flow sibling that is not self-collapsing. | 
| +    // "If the top and bottom margins of an element with clearance are | 
| +    // adjoining, its margins collapse with the adjoining margins of following | 
| +    // siblings but that resulting margin does not collapse with the bottom | 
| +    // margin of the parent block." | 
| +    // So the parent's bottom margin cannot collapse through this block or any | 
| +    // subsequent self-collapsing blocks. Set a bit to ensure this happens; it | 
| +    // will get reset if we encounter an in-flow sibling that is not | 
| +    // self-collapsing. | 
| marginInfo.setCanCollapseMarginAfterWithLastChild(false); | 
|  | 
| -    // For now set the border-top of |child| flush with the bottom border-edge of the float so it can layout any floating or positioned children of | 
| -    // its own at the correct vertical position. If subsequent siblings attempt to collapse with |child|'s margins in |collapseMargins| we will | 
| -    // adjust the height of the parent to |child|'s margin top (which if it is positive sits up 'inside' the float it's clearing) so that all three | 
| -    // margins can collapse at the correct vertical position. | 
| -    // Per CSS2.1 we need to ensure that any negative margin-top clears |child| beyond the bottom border-edge of the float so that the top border edge of the child | 
| -    // (i.e. its clearance)  is at a position that satisfies the equation: "the amount of clearance is set so that clearance + margin-top = [height of float], | 
| +    // For now set the border-top of |child| flush with the bottom border-edge | 
| +    // of the float so it can layout any floating or positioned children of its | 
| +    // own at the correct vertical position. If subsequent siblings attempt to | 
| +    // collapse with |child|'s margins in |collapseMargins| we will adjust the | 
| +    // height of the parent to |child|'s margin top (which if it is positive | 
| +    // sits up 'inside' the float it's clearing) so that all three margins can | 
| +    // collapse at the correct vertical position. | 
| +    // Per CSS2.1 we need to ensure that any negative margin-top clears |child| | 
| +    // beyond the bottom border-edge of the float so that the top border edge of | 
| +    // the child (i.e. its clearance)  is at a position that satisfies the | 
| +    // equation: "the amount of clearance is set so that: | 
| +    //   clearance + margin-top = [height of float], | 
| // i.e., clearance = [height of float] - margin-top". | 
| setLogicalHeight(child.logicalTop() + childMargins.negativeMarginBefore()); | 
| } else { | 
| @@ -1776,7 +1880,8 @@ LayoutUnit LayoutBlockFlow::clearFloatsIfNeeded(LayoutBox& child, | 
| setMaxMarginBeforeValues(oldTopPosMargin, oldTopNegMargin); | 
| marginInfo.setAtBeforeSideOfBlock(false); | 
|  | 
| -    // In case the child discarded the before margin of the block we need to reset the mustDiscardMarginBefore flag to the initial value. | 
| +    // In case the child discarded the before margin of the block we need to | 
| +    // reset the mustDiscardMarginBefore flag to the initial value. | 
| setMustDiscardMarginBefore(style()->marginBeforeCollapse() == | 
| MarginCollapseDiscard); | 
| } | 
| @@ -1787,15 +1892,16 @@ LayoutUnit LayoutBlockFlow::clearFloatsIfNeeded(LayoutBox& child, | 
| void LayoutBlockFlow::setCollapsedBottomMargin(const MarginInfo& marginInfo) { | 
| if (marginInfo.canCollapseWithMarginAfter() && | 
| !marginInfo.canCollapseWithMarginBefore()) { | 
| -    // Update the after side margin of the container to discard if the after margin of the last child also discards and we collapse with it. | 
| +    // Update the after side margin of the container to discard if the after | 
| +    // margin of the last child also discards and we collapse with it. | 
| // Don't update the max margin values because we won't need them anyway. | 
| if (marginInfo.discardMargin()) { | 
| setMustDiscardMarginAfter(); | 
| return; | 
| } | 
|  | 
| -    // Update our max pos/neg bottom margins, since we collapsed our bottom margins | 
| -    // with our children. | 
| +    // Update our max pos/neg bottom margins, since we collapsed our bottom | 
| +    // margins with our children. | 
| setMaxMarginAfterValues( | 
| std::max(maxPositiveMarginAfter(), marginInfo.positiveMargin()), | 
| std::max(maxNegativeMarginAfter(), marginInfo.negativeMargin())); | 
| @@ -1818,15 +1924,18 @@ void LayoutBlockFlow::marginBeforeEstimateForChild( | 
| LayoutUnit& positiveMarginBefore, | 
| LayoutUnit& negativeMarginBefore, | 
| bool& discardMarginBefore) const { | 
| -  // Give up if in quirks mode and we're a body/table cell and the top margin of the child box is quirky. | 
| -  // Give up if the child specified -webkit-margin-collapse: separate that prevents collapsing. | 
| +  // Give up if in quirks mode and we're a body/table cell and the top margin of | 
| +  // the child box is quirky. | 
| +  // Give up if the child specified -webkit-margin-collapse: separate that | 
| +  // prevents collapsing. | 
| // FIXME: Use writing mode independent accessor for marginBeforeCollapse. | 
| if ((document().inQuirksMode() && hasMarginBeforeQuirk(&child) && | 
| (isTableCell() || isBody())) || | 
| child.style()->marginBeforeCollapse() == MarginCollapseSeparate) | 
| return; | 
|  | 
| -  // The margins are discarded by a child that specified -webkit-margin-collapse: discard. | 
| +  // The margins are discarded by a child that specified | 
| +  // -webkit-margin-collapse: discard. | 
| // FIXME: Use writing mode independent accessor for marginBeforeCollapse. | 
| if (child.style()->marginBeforeCollapse() == MarginCollapseDiscard) { | 
| positiveMarginBefore = LayoutUnit(); | 
| @@ -1863,7 +1972,8 @@ void LayoutBlockFlow::marginBeforeEstimateForChild( | 
| if (!grandchildBox) | 
| return; | 
|  | 
| -  // Make sure to update the block margins now for the grandchild box so that we're looking at current values. | 
| +  // Make sure to update the block margins now for the grandchild box so that | 
| +  // we're looking at current values. | 
| if (grandchildBox->needsLayout()) { | 
| grandchildBox->computeAndSetBlockDirectionMargins(this); | 
| if (grandchildBox->isLayoutBlock()) { | 
| @@ -1875,14 +1985,16 @@ void LayoutBlockFlow::marginBeforeEstimateForChild( | 
| } | 
| } | 
|  | 
| -  // If we have a 'clear' value but also have a margin we may not actually require clearance to move past any floats. | 
| -  // If that's the case we want to be sure we estimate the correct position including margins after any floats rather | 
| -  // than use 'clearance' later which could give us the wrong position. | 
| +  // If we have a 'clear' value but also have a margin we may not actually | 
| +  // require clearance to move past any floats. If that's the case we want to be | 
| +  // sure we estimate the correct position including margins after any floats | 
| +  // rather than use 'clearance' later which could give us the wrong position. | 
| if (grandchildBox->style()->clear() != ClearNone && | 
| childBlockFlow->marginBeforeForChild(*grandchildBox) == 0) | 
| return; | 
|  | 
| -  // Collapse the margin of the grandchild box with our own to produce an estimate. | 
| +  // Collapse the margin of the grandchild box with our own to produce an | 
| +  // estimate. | 
| childBlockFlow->marginBeforeEstimateForChild( | 
| *grandchildBox, positiveMarginBefore, negativeMarginBefore, | 
| discardMarginBefore); | 
| @@ -1893,7 +2005,8 @@ LayoutUnit LayoutBlockFlow::estimateLogicalTopPosition( | 
| const BlockChildrenLayoutInfo& layoutInfo, | 
| LayoutUnit& estimateWithoutPagination) { | 
| const MarginInfo& marginInfo = layoutInfo.marginInfo(); | 
| -  // FIXME: We need to eliminate the estimation of vertical position, because when it's wrong we sometimes trigger a pathological | 
| +  // FIXME: We need to eliminate the estimation of vertical position, because | 
| +  // when it's wrong we sometimes trigger a pathological | 
| // relayout if there are intruding floats. | 
| LayoutUnit logicalTopEstimate = logicalHeight(); | 
| LayoutUnit positiveMarginBefore; | 
| @@ -1905,8 +2018,8 @@ LayoutUnit LayoutBlockFlow::estimateLogicalTopPosition( | 
| marginBeforeEstimateForChild(child, positiveMarginBefore, | 
| negativeMarginBefore, discardMarginBefore); | 
| } else { | 
| -      // Use the cached collapsed margin values from a previous layout. Most of the time they | 
| -      // will be right. | 
| +      // Use the cached collapsed margin values from a previous layout. Most of | 
| +      // the time they will be right. | 
| LayoutBlockFlow::MarginValues marginValues = marginValuesForChild(child); | 
| positiveMarginBefore = | 
| std::max(positiveMarginBefore, marginValues.positiveMarginBefore()); | 
| @@ -1922,8 +2035,8 @@ LayoutUnit LayoutBlockFlow::estimateLogicalTopPosition( | 
| std::max(marginInfo.negativeMargin(), negativeMarginBefore); | 
| } | 
|  | 
| -  // Adjust logicalTopEstimate down to the next page if the margins are so large that we don't fit on the current | 
| -  // page. | 
| +  // Adjust logicalTopEstimate down to the next page if the margins are so large | 
| +  // that we don't fit on the current page. | 
| LayoutState* layoutState = view()->layoutState(); | 
| if (layoutState->isPaginated() && isPageLogicalHeightKnown(logicalHeight()) && | 
| logicalTopEstimate > logicalHeight()) | 
| @@ -1936,17 +2049,18 @@ LayoutUnit LayoutBlockFlow::estimateLogicalTopPosition( | 
|  | 
| if (layoutState->isPaginated()) { | 
| if (!layoutInfo.isAtFirstInFlowChild()) { | 
| -      // Estimate the need for a forced break in front of this child. The final break policy | 
| -      // at this class A break point isn't known until we have laid out the children of | 
| -      // |child|. There may be forced break-before values set on first-children inside that | 
| -      // get propagated up to the child. Just make an estimate with what we know so far. | 
| +      // Estimate the need for a forced break in front of this child. The final | 
| +      // break policy at this class A break point isn't known until we have laid | 
| +      // out the children of |child|. There may be forced break-before values | 
| +      // set on first-children inside that get propagated up to the child. | 
| +      // Just make an estimate with what we know so far. | 
| EBreak breakValue = | 
| child.classABreakPointValue(layoutInfo.previousBreakAfterValue()); | 
| if (isForcedFragmentainerBreakValue(breakValue)) { | 
| logicalTopEstimate = applyForcedBreak(logicalHeight(), breakValue); | 
| -        // Disregard previous margins, since they will collapse with the fragmentainer | 
| -        // boundary, due to the forced break. Only apply margins that have been specified | 
| -        // on the child or its descendants. | 
| +        // Disregard previous margins, since they will collapse with the | 
| +        // fragmentainer boundary, due to the forced break. Only apply margins | 
| +        // that have been specified on the child or its descendants. | 
| if (!discardMarginBefore) | 
| logicalTopEstimate += positiveMarginBefore - negativeMarginBefore; | 
|  | 
| @@ -1956,7 +2070,8 @@ LayoutUnit LayoutBlockFlow::estimateLogicalTopPosition( | 
| } | 
| } | 
|  | 
| -    // For replaced elements and scrolled elements, we want to shift them to the next page if they don't fit on the current one. | 
| +    // For replaced elements and scrolled elements, we want to shift them to the | 
| +    // next page if they don't fit on the current one. | 
| logicalTopEstimate = adjustForUnsplittableChild(child, logicalTopEstimate); | 
| } | 
|  | 
| @@ -1973,8 +2088,8 @@ void LayoutBlockFlow::adjustFloatingBlock(const MarginInfo& marginInfo) { | 
| // | 
| // Note also that the previous flow may collapse its margin into the top of | 
| // our block. If this is the case, then we do not add the margin in to our | 
| -  // height when computing the position of the float. This condition can be tested | 
| -  // for by simply calling canCollapseWithMarginBefore. See | 
| +  // height when computing the position of the float. This condition can be | 
| +  // tested for by simply calling canCollapseWithMarginBefore. See | 
| // http://www.hixie.ch/tests/adhoc/css/box/block/margin-collapse/046.html for | 
| // an example of this scenario. | 
| LayoutUnit marginOffset = marginInfo.canCollapseWithMarginBefore() | 
| @@ -1991,9 +2106,11 @@ void LayoutBlockFlow::handleAfterSideOfBlock(LayoutBox* lastChild, | 
| MarginInfo& marginInfo) { | 
| marginInfo.setAtAfterSideOfBlock(true); | 
|  | 
| -  // If our last child was a self-collapsing block with clearance then our logical height is flush with the | 
| -  // bottom edge of the float that the child clears. The correct vertical position for the margin-collapsing we want | 
| -  // to perform now is at the child's margin-top - so adjust our height to that position. | 
| +  // If our last child was a self-collapsing block with clearance then our | 
| +  // logical height is flush with the bottom edge of the float that the child | 
| +  // clears. The correct vertical position for the margin-collapsing we want to | 
| +  // perform now is at the child's margin-top - so adjust our height to that | 
| +  // position. | 
| if (marginInfo.lastChildIsSelfCollapsingBlockWithClearance()) { | 
| ASSERT(lastChild); | 
| setLogicalHeight(logicalHeight() - | 
| @@ -2004,7 +2121,8 @@ void LayoutBlockFlow::handleAfterSideOfBlock(LayoutBox* lastChild, | 
| !marginInfo.canCollapseMarginAfterWithLastChild()) | 
| marginInfo.setCanCollapseMarginAfterWithChildren(false); | 
|  | 
| -  // If we can't collapse with children then go ahead and add in the bottom margin. | 
| +  // If we can't collapse with children then go ahead and add in the bottom | 
| +  // margin. | 
| if (!marginInfo.discardMargin() && | 
| (!marginInfo.canCollapseWithMarginAfter() && | 
| !marginInfo.canCollapseWithMarginBefore() && | 
| @@ -2015,17 +2133,18 @@ void LayoutBlockFlow::handleAfterSideOfBlock(LayoutBox* lastChild, | 
| // Now add in our bottom border/padding. | 
| setLogicalHeight(logicalHeight() + afterSide); | 
|  | 
| -  // Negative margins can cause our height to shrink below our minimal height (border/padding). | 
| -  // If this happens, ensure that the computed height is increased to the minimal height. | 
| +  // Negative margins can cause our height to shrink below our minimal height | 
| +  // (border/padding). If this happens, ensure that the computed height is | 
| +  // increased to the minimal height. | 
| setLogicalHeight(std::max(logicalHeight(), beforeSide + afterSide)); | 
|  | 
| // Update our bottom collapsed margin info. | 
| setCollapsedBottomMargin(marginInfo); | 
|  | 
| -  // There's no class A break point right after the last child, only *between* siblings. So | 
| -  // propagate the break-after value, and keep looking for a class A break point (at the next | 
| -  // in-flow block-level object), where we'll join this break-after value with the break-before | 
| -  // value there. | 
| +  // There's no class A break point right after the last child, only *between* | 
| +  // siblings. So propagate the break-after value, and keep looking for a class | 
| +  // A break point (at the next in-flow block-level object), where we'll join | 
| +  // this break-after value with the break-before value there. | 
| if (view()->layoutState()->isPaginated() && lastChild) | 
| setBreakAfter( | 
| joinFragmentainerBreakValues(breakAfter(), lastChild->breakAfter())); | 
| @@ -2085,8 +2204,10 @@ bool LayoutBlockFlow::mustDiscardMarginBeforeForChild( | 
| : (child.style()->marginAfterCollapse() == | 
| MarginCollapseDiscard); | 
|  | 
| -  // FIXME: We return false here because the implementation is not geometrically complete. We have values only for before/after, not start/end. | 
| -  // In case the boxes are perpendicular we assume the property is not specified. | 
| +  // FIXME: We return false here because the implementation is not geometrically | 
| +  // complete. We have values only for before/after, not start/end. | 
| +  // In case the boxes are perpendicular we assume the property is not | 
| +  // specified. | 
| return false; | 
| } | 
|  | 
| @@ -2160,17 +2281,20 @@ LayoutUnit LayoutBlockFlow::applyForcedBreak(LayoutUnit logicalOffset, | 
| EBreak breakValue) { | 
| if (!isForcedFragmentainerBreakValue(breakValue)) | 
| return logicalOffset; | 
| -  // TODO(mstensho): honor breakValue. There are different types of forced breaks. We currently | 
| -  // just assume that we want to break to the top of the next fragmentainer of the fragmentation | 
| -  // context we're in. However, we may want to find the next left or right page - even if we're | 
| -  // inside a multicol container when printing. | 
| +  // TODO(mstensho): honor breakValue. There are different types of forced | 
| +  // breaks. We currently just assume that we want to break to the top of the | 
| +  // next fragmentainer of the fragmentation context we're in. However, we may | 
| +  // want to find the next left or right page - even if we're inside a multicol | 
| +  // container when printing. | 
| LayoutUnit pageLogicalHeight = pageLogicalHeightForOffset(logicalOffset); | 
| if (!pageLogicalHeight) | 
| -    return logicalOffset;  // Page height is still unknown, so we cannot insert forced breaks. | 
| +    return logicalOffset;  // Page height is still unknown, so we cannot insert | 
| +                           // forced breaks. | 
| LayoutUnit remainingLogicalHeight = pageRemainingLogicalHeightForOffset( | 
| logicalOffset, AssociateWithLatterPage); | 
| if (remainingLogicalHeight == pageLogicalHeight) | 
| -    return logicalOffset;  // Don't break if we're already at the block start of a fragmentainer. | 
| +    return logicalOffset;  // Don't break if we're already at the block start of | 
| +                           // a fragmentainer. | 
| return logicalOffset + remainingLogicalHeight; | 
| } | 
|  | 
| @@ -2238,7 +2362,8 @@ void LayoutBlockFlow::computeSelfHitTestRects( | 
| std::min<LayoutUnit>(curr->lineBottom(), curr->top() + curr->height()); | 
| LayoutRect rect(layerOffset.x() + curr->x(), layerOffset.y() + top, | 
| curr->width(), bottom - top); | 
| -    // It's common for this rect to be entirely contained in our box, so exclude that simple case. | 
| +    // It's common for this rect to be entirely contained in our box, so exclude | 
| +    // that simple case. | 
| if (!rect.isEmpty() && (rects.isEmpty() || !rects[0].contains(rect))) | 
| rects.append(rect); | 
| } | 
| @@ -2251,9 +2376,9 @@ void LayoutBlockFlow::absoluteRects( | 
| LayoutBlock::absoluteRects(rects, accumulatedOffset); | 
| return; | 
| } | 
| -  // For blocks inside inlines, we go ahead and include margins so that we run right up to the | 
| -  // inline boxes above and below us (thus getting merged with them to form a single irregular | 
| -  // shape). | 
| +  // For blocks inside inlines, we go ahead and include margins so that we run | 
| +  // right up to the inline boxes above and below us (thus getting merged with | 
| +  // them to form a single irregular shape). | 
| // FIXME: This is wrong for vertical writing-modes. | 
| // https://bugs.webkit.org/show_bug.cgi?id=46781 | 
| LayoutRect rect(accumulatedOffset, size()); | 
| @@ -2272,9 +2397,9 @@ void LayoutBlockFlow::absoluteQuads(Vector<FloatQuad>& quads) const { | 
| LayoutBlock::absoluteQuads(quads); | 
| return; | 
| } | 
| -  // For blocks inside inlines, we go ahead and include margins so that we run right up to the | 
| -  // inline boxes above and below us (thus getting merged with them to form a single irregular | 
| -  // shape). | 
| +  // For blocks inside inlines, we go ahead and include margins so that we run | 
| +  // right up to the inline boxes above and below us (thus getting merged with | 
| +  // them to form a single irregular shape). | 
| // FIXME: This is wrong for vertical writing-modes. | 
| // https://bugs.webkit.org/show_bug.cgi?id=46781 | 
| LayoutRect localRect(LayoutPoint(), size()); | 
| @@ -2347,7 +2472,8 @@ int LayoutBlockFlow::inlineBlockBaseline( | 
| if ((!style()->isOverflowVisible() && | 
| !shouldIgnoreOverflowPropertyForInlineBlockBaseline()) || | 
| style()->containsSize()) { | 
| -    // We are not calling baselinePosition here because the caller should add the margin-top/margin-right, not us. | 
| +    // We are not calling baselinePosition here because the caller should add | 
| +    // the margin-top/margin-right, not us. | 
| return (lineDirection == HorizontalLine ? size().height() + marginBottom() | 
| : size().width() + marginLeft()) | 
| .toInt(); | 
| @@ -2380,14 +2506,17 @@ void LayoutBlockFlow::removeFloatingObjectsFromDescendants() { | 
| removeFloatingObjects(); | 
| setChildNeedsLayout(MarkOnlyThis); | 
|  | 
| -  // If our children are inline, then the only boxes which could contain floats are atomic inlines (e.g. inline-block, float etc.) | 
| -  // and these create formatting contexts, so can't pick up intruding floats from ancestors/siblings - making them safe to skip. | 
| +  // If our children are inline, then the only boxes which could contain floats | 
| +  // are atomic inlines (e.g. inline-block, float etc.) and these create | 
| +  // formatting contexts, so can't pick up intruding floats from | 
| +  // ancestors/siblings - making them safe to skip. | 
| if (childrenInline()) | 
| return; | 
| for (LayoutObject* child = firstChild(); child; | 
| child = child->nextSibling()) { | 
| -    // We don't skip blocks that create formatting contexts as they may have only recently | 
| -    // changed style and their float lists may still contain floats from siblings and ancestors. | 
| +    // We don't skip blocks that create formatting contexts as they may have | 
| +    // only recently changed style and their float lists may still contain | 
| +    // floats from siblings and ancestors. | 
| if (child->isLayoutBlockFlow()) | 
| toLayoutBlockFlow(child)->removeFloatingObjectsFromDescendants(); | 
| } | 
| @@ -2409,9 +2538,11 @@ void LayoutBlockFlow::markAllDescendantsWithFloatsForLayout( | 
| if (floatToRemove) | 
| removeFloatingObject(floatToRemove); | 
|  | 
| -  // Iterate over our children and mark them as needed. If our children are inline, then the | 
| -  // only boxes which could contain floats are atomic inlines (e.g. inline-block, float etc.) and these create formatting | 
| -  // contexts, so can't pick up intruding floats from ancestors/siblings - making them safe to skip. | 
| +  // Iterate over our children and mark them as needed. If our children are | 
| +  // inline, then the only boxes which could contain floats are atomic inlines | 
| +  // (e.g. inline-block, float etc.) and these create formatting contexts, so | 
| +  // can't pick up intruding floats from ancestors/siblings - making them safe | 
| +  // to skip. | 
| if (!childrenInline()) { | 
| for (LayoutObject* child = firstChild(); child; | 
| child = child->nextSibling()) { | 
| @@ -2466,7 +2597,8 @@ LayoutUnit LayoutBlockFlow::getClearDelta(LayoutBox* child, | 
| if (!containsFloats()) | 
| return LayoutUnit(); | 
|  | 
| -  // At least one float is present. We need to perform the clearance computation. | 
| +  // At least one float is present. We need to perform the clearance | 
| +  // computation. | 
| bool clearSet = child->style()->clear() != ClearNone; | 
| LayoutUnit logicalBottom; | 
| switch (child->style()->clear()) { | 
| @@ -2483,7 +2615,8 @@ LayoutUnit LayoutBlockFlow::getClearDelta(LayoutBox* child, | 
| break; | 
| } | 
|  | 
| -  // We also clear floats if we are too big to sit on the same line as a float (and wish to avoid floats by default). | 
| +  // We also clear floats if we are too big to sit on the same line as a float | 
| +  // (and wish to avoid floats by default). | 
| LayoutUnit result = clearSet | 
| ? (logicalBottom - logicalTop).clampNegativeToZero() | 
| : LayoutUnit(); | 
| @@ -2508,9 +2641,12 @@ LayoutUnit LayoutBlockFlow::getClearDelta(LayoutBox* child, | 
|  | 
| if (childLogicalWidthAtNewLogicalTopOffset <= | 
| availableLogicalWidthAtNewLogicalTopOffset) { | 
| -        // Even though we may not be moving, if the logical width did shrink because of the presence of new floats, then | 
| -        // we need to force a relayout as though we shifted. This happens because of the dynamic addition of overhanging floats | 
| -        // from previous siblings when negative margins exist on a child (see the addOverhangingFloats call at the end of collapseMargins). | 
| +        // Even though we may not be moving, if the logical width did shrink | 
| +        // because of the presence of new floats, then we need to force a | 
| +        // relayout as though we shifted. This happens because of the dynamic | 
| +        // addition of overhanging floats from previous siblings when negative | 
| +        // margins exist on a child (see the addOverhangingFloats call at the | 
| +        // end of collapseMargins). | 
| if (childLogicalWidthAtOldLogicalTopOffset != | 
| childLogicalWidthAtNewLogicalTopOffset) | 
| child->setChildNeedsLayout(MarkOnlyThis); | 
| @@ -2536,13 +2672,16 @@ void LayoutBlockFlow::willBeDestroyed() { | 
| // Mark as being destroyed to avoid trouble with merges in removeChild(). | 
| m_beingDestroyed = true; | 
|  | 
| -  // Make sure to destroy anonymous children first while they are still connected to the rest of the tree, so that they will | 
| -  // properly dirty line boxes that they are removed from. Effects that do :before/:after only on hover could crash otherwise. | 
| +  // Make sure to destroy anonymous children first while they are still | 
| +  // connected to the rest of the tree, so that they will properly dirty line | 
| +  // boxes that they are removed from. Effects that do :before/:after only on | 
| +  // hover could crash otherwise. | 
| children()->destroyLeftoverChildren(); | 
|  | 
| // Destroy our continuation before anything other than anonymous children. | 
| // The reason we don't destroy it before anonymous children is that they may | 
| -  // have continuations of their own that are anonymous children of our continuation. | 
| +  // have continuations of their own that are anonymous children of our | 
| +  // continuation. | 
| LayoutBoxModelObject* continuation = this->continuation(); | 
| if (continuation) { | 
| continuation->destroy(); | 
| @@ -2550,8 +2689,8 @@ void LayoutBlockFlow::willBeDestroyed() { | 
| } | 
|  | 
| if (!documentBeingDestroyed()) { | 
| -    // TODO(mstensho): figure out if we need this. We have no test coverage for it. It looks | 
| -    // like all line boxes have been removed at this point. | 
| +    // TODO(mstensho): figure out if we need this. We have no test coverage for | 
| +    // it. It looks like all line boxes have been removed at this point. | 
| if (firstLineBox()) { | 
| // We can't wait for LayoutBox::destroy to clear the selection, | 
| // because by then we will have nuked the line boxes. | 
| @@ -2598,18 +2737,20 @@ void LayoutBlockFlow::styleDidChange(StyleDifference diff, | 
| bool hadSelfPaintingLayer = hasSelfPaintingLayer(); | 
| LayoutBlock::styleDidChange(diff, oldStyle); | 
|  | 
| -  // After our style changed, if we lose our ability to propagate floats into next sibling | 
| -  // blocks, then we need to find the top most parent containing that overhanging float and | 
| -  // then mark its descendants with floats for layout and clear all floats from its next | 
| -  // sibling blocks that exist in our floating objects list. See bug 56299 and 62875. | 
| +  // After our style changed, if we lose our ability to propagate floats into | 
| +  // next sibling blocks, then we need to find the top most parent containing | 
| +  // that overhanging float and then mark its descendants with floats for layout | 
| +  // and clear all floats from its next sibling blocks that exist in our | 
| +  // floating objects list. See crbug.com/56299 and crbug.com/62875. | 
| bool canPropagateFloatIntoSibling = | 
| !isFloatingOrOutOfFlowPositioned() && !avoidsFloats(); | 
| bool siblingFloatPropagationChanged = | 
| diff.needsFullLayout() && s_canPropagateFloatIntoSibling && | 
| !canPropagateFloatIntoSibling && hasOverhangingFloats(); | 
|  | 
| -  // When this object's self-painting layer status changed, we should update FloatingObjects::shouldPaint() flags for | 
| -  // descendant overhanging floats in ancestors. | 
| +  // When this object's self-painting layer status changed, we should update | 
| +  // FloatingObjects::shouldPaint() flags for descendant overhanging floats in | 
| +  // ancestors. | 
| bool needsUpdateAncestorFloatObjectShouldPaintFlags = false; | 
| if (hasSelfPaintingLayer() != hadSelfPaintingLayer && | 
| hasOverhangingFloats()) { | 
| @@ -2654,8 +2795,8 @@ void LayoutBlockFlow::styleDidChange(StyleDifference diff, | 
| if (oldStyle) { | 
| if (LayoutMultiColumnFlowThread* flowThread = multiColumnFlowThread()) { | 
| if (!style()->columnRuleEquivalent(oldStyle)) { | 
| -        // Column rules are painted by anonymous column set children of the multicol | 
| -        // container. We need to notify them. | 
| +        // Column rules are painted by anonymous column set children of the | 
| +        // multicol container. We need to notify them. | 
| flowThread->columnRuleStyleDidChange(); | 
| } | 
| } | 
| @@ -2711,15 +2852,16 @@ void LayoutBlockFlow::addChild(LayoutObject* newChild, | 
|  | 
| bool madeBoxesNonInline = false; | 
|  | 
| -  // A block has to either have all of its children inline, or all of its children as blocks. | 
| -  // So, if our children are currently inline and a block child has to be inserted, we move all our | 
| -  // inline children into anonymous block boxes. | 
| +  // A block has to either have all of its children inline, or all of its | 
| +  // children as blocks. | 
| +  // So, if our children are currently inline and a block child has to be | 
| +  // inserted, we move all our inline children into anonymous block boxes. | 
| bool childIsBlockLevel = | 
| !newChild->isInline() && !newChild->isFloatingOrOutOfFlowPositioned(); | 
| if (childrenInline()) { | 
| if (childIsBlockLevel) { | 
| -      // Wrap the inline content in anonymous blocks, to allow for the new block child to be | 
| -      // inserted. | 
| +      // Wrap the inline content in anonymous blocks, to allow for the new block | 
| +      // child to be inserted. | 
| makeChildrenNonInline(beforeChild); | 
| madeBoxesNonInline = true; | 
|  | 
| @@ -2730,11 +2872,12 @@ void LayoutBlockFlow::addChild(LayoutObject* newChild, | 
| } | 
| } | 
| } else if (!childIsBlockLevel) { | 
| -    // This block has block children. We may want to put the new child into an anomyous | 
| -    // block. Floats and out-of-flow children may live among either block or inline children, | 
| -    // so for such children, only put them inside an anonymous block if one already exists. If | 
| -    // the child is inline, on the other hand, we *have to* put it inside an anonymous block, | 
| -    // so create a new one if there is none for us there already. | 
| +    // This block has block children. We may want to put the new child into an | 
| +    // anomyous block. Floats and out-of-flow children may live among either | 
| +    // block or inline children, so for such children, only put them inside an | 
| +    // anonymous block if one already exists. If the child is inline, on the | 
| +    // other hand, we *have to* put it inside an anonymous block, so create a | 
| +    // new one if there is none for us there already. | 
| LayoutObject* afterChild = | 
| beforeChild ? beforeChild->previousSibling() : lastChild(); | 
|  | 
| @@ -2755,8 +2898,9 @@ void LayoutBlockFlow::addChild(LayoutObject* newChild, | 
| } | 
| } | 
|  | 
| -  // Skip the LayoutBlock override, since that one deals with anonymous child insertion in a way | 
| -  // that isn't sufficient for us, and can only cause trouble at this point. | 
| +  // Skip the LayoutBlock override, since that one deals with anonymous child | 
| +  // insertion in a way that isn't sufficient for us, and can only cause trouble | 
| +  // at this point. | 
| LayoutBox::addChild(newChild, beforeChild); | 
|  | 
| if (madeBoxesNonInline && parent() && isAnonymousBlock() && | 
| @@ -2846,7 +2990,8 @@ void LayoutBlockFlow::removeChild(LayoutObject* oldChild) { | 
| } else if (!beingDestroyed() && | 
| !oldChild->isFloatingOrOutOfFlowPositioned() && | 
| !oldChild->isAnonymousBlock()) { | 
| -    // If the child we're removing means that we can now treat all children as inline without the need for anonymous blocks, then do that. | 
| +    // If the child we're removing means that we can now treat all children as | 
| +    // inline without the need for anonymous blocks, then do that. | 
| makeChildrenInlineIfPossible(); | 
| } | 
| } | 
| @@ -2861,14 +3006,14 @@ void LayoutBlockFlow::moveAllChildrenIncludingFloatsTo(LayoutBlock* toBlock, | 
| // anonymous block later in the tree is merged into the one preceding it. | 
| // It can happen that the later block (this) contains floats that the | 
| // previous block (toBlockFlow) did not contain, and thus are not in the | 
| -  // floating objects list for toBlockFlow. This can result in toBlockFlow containing | 
| -  // floats that are not in it's floating objects list, but are in the | 
| -  // floating objects lists of siblings and parents. This can cause problems | 
| -  // when the float itself is deleted, since the deletion code assumes that | 
| -  // if a float is not in it's containing block's floating objects list, it | 
| -  // isn't in any floating objects list. In order to preserve this condition | 
| -  // (removing it has serious performance implications), we need to copy the | 
| -  // floating objects from the old block (this) to the new block (toBlockFlow). | 
| +  // floating objects list for toBlockFlow. This can result in toBlockFlow | 
| +  // containing floats that are not in it's floating objects list, but are in | 
| +  // the floating objects lists of siblings and parents. This can cause problems | 
| +  // when the float itself is deleted, since the deletion code assumes that if a | 
| +  // float is not in it's containing block's floating objects list, it isn't in | 
| +  // any floating objects list. In order to preserve this condition (removing it | 
| +  // has serious performance implications), we need to copy the floating objects | 
| +  // from the old block (this) to the new block (toBlockFlow). | 
| // The float's metrics will likely all be wrong, but since toBlockFlow is | 
| // already marked for layout, this will get fixed before anything gets | 
| // displayed. | 
| @@ -2901,8 +3046,8 @@ void LayoutBlockFlow::childBecameFloatingOrOutOfFlow(LayoutBox* child) { | 
| if (prev && prev->isAnonymousBlock() && prev->isLayoutBlockFlow()) { | 
| LayoutBlockFlow* newContainer = toLayoutBlockFlow(prev); | 
| moveChildTo(newContainer, child, nullptr, false); | 
| -    // The anonymous block we've moved to may now be adjacent to former siblings of ours | 
| -    // that it can contain also. | 
| +    // The anonymous block we've moved to may now be adjacent to former siblings | 
| +    // of ours that it can contain also. | 
| newContainer->reparentSubsequentFloatingOrOutOfFlowSiblings(); | 
| return; | 
| } | 
| @@ -2921,7 +3066,8 @@ void LayoutBlockFlow::collapseAnonymousBlockChild(LayoutBlockFlow* child) { | 
| return; | 
| if (child->continuation()) | 
| return; | 
| -  // Ruby elements use anonymous wrappers for ruby runs and ruby bases by design, so we don't remove them. | 
| +  // Ruby elements use anonymous wrappers for ruby runs and ruby bases by | 
| +  // design, so we don't remove them. | 
| if (child->isRubyRun() || child->isRubyBase()) | 
| return; | 
| setNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation( | 
| @@ -2936,8 +3082,9 @@ void LayoutBlockFlow::collapseAnonymousBlockChild(LayoutBlockFlow* child) { | 
|  | 
| bool LayoutBlockFlow::mergeSiblingContiguousAnonymousBlock( | 
| LayoutBlockFlow* siblingThatMayBeDeleted) { | 
| -  // Note: |this| and |siblingThatMayBeDeleted| may not be adjacent siblings at this point. There | 
| -  // may be an object between them which is about to be removed. | 
| +  // Note: |this| and |siblingThatMayBeDeleted| may not be adjacent siblings at | 
| +  // this point. There may be an object between them which is about to be | 
| +  // removed. | 
|  | 
| if (!isMergeableAnonymousBlock(this) || | 
| !isMergeableAnonymousBlock(siblingThatMayBeDeleted)) | 
| @@ -2946,8 +3093,8 @@ bool LayoutBlockFlow::mergeSiblingContiguousAnonymousBlock( | 
| setNeedsLayoutAndPrefWidthsRecalcAndFullPaintInvalidation( | 
| LayoutInvalidationReason::AnonymousBlockChange); | 
|  | 
| -  // If the inlineness of children of the two block don't match, we'd need special code here | 
| -  // (but there should be no need for it). | 
| +  // If the inlineness of children of the two block don't match, we'd need | 
| +  // special code here (but there should be no need for it). | 
| ASSERT(siblingThatMayBeDeleted->childrenInline() == childrenInline()); | 
| // Take all the children out of the |next| block and put them in | 
| // the |prev| block. | 
| @@ -2993,7 +3140,8 @@ void LayoutBlockFlow::reparentPrecedingFloatingOrOutOfFlowSiblings() { | 
| } | 
|  | 
| void LayoutBlockFlow::makeChildrenInlineIfPossible() { | 
| -  // Collapsing away anonymous wrappers isn't relevant for the children of anonymous blocks, unless they are ruby bases. | 
| +  // Collapsing away anonymous wrappers isn't relevant for the children of | 
| +  // anonymous blocks, unless they are ruby bases. | 
| if (isAnonymousBlock() && !isRubyBase()) | 
| return; | 
|  | 
| @@ -3005,29 +3153,35 @@ void LayoutBlockFlow::makeChildrenInlineIfPossible() { | 
| if (child->isOutOfFlowPositioned()) | 
| continue; | 
|  | 
| -    // There are still block children in the container, so any anonymous wrappers are still needed. | 
| +    // There are still block children in the container, so any anonymous | 
| +    // wrappers are still needed. | 
| if (!child->isAnonymousBlock() || !child->isLayoutBlockFlow()) | 
| return; | 
| -    // If one of the children is being destroyed then it is unsafe to clean up anonymous wrappers as the | 
| +    // If one of the children is being destroyed then it is unsafe to clean up | 
| +    // anonymous wrappers as the | 
| // entire branch may be being destroyed. | 
| if (toLayoutBlockFlow(child)->beingDestroyed()) | 
| return; | 
| -    // We can't remove anonymous wrappers if they contain continuations as this means there are block children present. | 
| +    // We can't remove anonymous wrappers if they contain continuations as this | 
| +    // means there are block children present. | 
| if (toLayoutBlockFlow(child)->continuation()) | 
| return; | 
| -    // We are only interested in removing anonymous wrappers if there are inline siblings underneath them. | 
| +    // We are only interested in removing anonymous wrappers if there are inline | 
| +    // siblings underneath them. | 
| if (!child->childrenInline()) | 
| return; | 
| -    // Ruby elements use anonymous wrappers for ruby runs and ruby bases by design, so we don't remove them. | 
| +    // Ruby elements use anonymous wrappers for ruby runs and ruby bases by | 
| +    // design, so we don't remove them. | 
| if (child->isRubyRun() || child->isRubyBase()) | 
| return; | 
|  | 
| blocksToRemove.append(toLayoutBlockFlow(child)); | 
| } | 
|  | 
| -  // If we make an object's children inline we are going to frustrate any future attempts to remove | 
| -  // floats from its children's float-lists before the next layout happens so clear down all the floatlists | 
| -  // now - they will be rebuilt at layout. | 
| +  // If we make an object's children inline we are going to frustrate any future | 
| +  // attempts to remove floats from its children's float-lists before the next | 
| +  // layout happens so clear down all the floatlists now - they will be rebuilt | 
| +  // at layout. | 
| removeFloatingObjectsFromDescendants(); | 
|  | 
| for (size_t i = 0; i < blocksToRemove.size(); i++) | 
| @@ -3047,9 +3201,9 @@ static void getInlineRun(LayoutObject* start, | 
| // We skip any non-inlines we encounter as long as we haven't found any | 
| // inlines yet. | 
| // | 
| -  // |boundary| indicates a non-inclusive boundary point.  Regardless of whether |boundary| | 
| -  // is inline or not, we will not include it in a run with inlines before it.  It's as though we encountered | 
| -  // a non-inline. | 
| +  // |boundary| indicates a non-inclusive boundary point.  Regardless of whether | 
| +  // |boundary| is inline or not, we will not include it in a run with inlines | 
| +  // before it. It's as though we encountered a non-inline. | 
|  | 
| // Start by skipping as many non-inlines as we can. | 
| LayoutObject* curr = start; | 
| @@ -3080,12 +3234,12 @@ static void getInlineRun(LayoutObject* start, | 
|  | 
| void LayoutBlockFlow::makeChildrenNonInline(LayoutObject* insertionPoint) { | 
| // makeChildrenNonInline takes a block whose children are *all* inline and it | 
| -  // makes sure that inline children are coalesced under anonymous | 
| -  // blocks.  If |insertionPoint| is defined, then it represents the insertion point for | 
| -  // the new block child that is causing us to have to wrap all the inlines.  This | 
| -  // means that we cannot coalesce inlines before |insertionPoint| with inlines following | 
| -  // |insertionPoint|, because the new child is going to be inserted in between the inlines, | 
| -  // splitting them. | 
| +  // makes sure that inline children are coalesced under anonymous blocks. | 
| +  // If |insertionPoint| is defined, then it represents the insertion point for | 
| +  // the new block child that is causing us to have to wrap all the inlines. | 
| +  // This means that we cannot coalesce inlines before |insertionPoint| with | 
| +  // inlines following |insertionPoint|, because the new child is going to be | 
| +  // inserted in between the inlines, splitting them. | 
| ASSERT(!isInline() || isAtomicInlineLevel()); | 
| ASSERT(!insertionPoint || insertionPoint->parent() == this); | 
|  | 
| @@ -3168,9 +3322,10 @@ LayoutPoint LayoutBlockFlow::flipFloatForWritingModeForChild( | 
| if (!style()->isFlippedBlocksWritingMode()) | 
| return point; | 
|  | 
| -  // This is similar to LayoutBox::flipForWritingModeForChild. We have to subtract out our left offsets twice, since | 
| -  // it's going to get added back in. We hide this complication here so that the calling code looks normal for the unflipped | 
| -  // case. | 
| +  // This is similar to LayoutBox::flipForWritingModeForChild. We have to | 
| +  // subtract out our left offsets twice, since it's going to get added back in. | 
| +  // We hide this complication here so that the calling code looks normal for | 
| +  // the unflipped case. | 
| return LayoutPoint(point.x() + size().width() - | 
| child.layoutObject()->size().width() - | 
| 2 * xPositionForFloatIncludingMargin(child), | 
| @@ -3313,8 +3468,8 @@ FloatingObject* LayoutBlockFlow::insertFloatingObject(LayoutBox& floatBox) { | 
|  | 
| std::unique_ptr<FloatingObject> newObj = FloatingObject::create(&floatBox); | 
|  | 
| -  // Our location is irrelevant if we're unsplittable or no pagination is in effect. | 
| -  // Just go ahead and lay out the float. | 
| +  // Our location is irrelevant if we're unsplittable or no pagination is in | 
| +  // effect. Just go ahead and lay out the float. | 
| bool isChildLayoutBlock = floatBox.isLayoutBlock(); | 
| if (isChildLayoutBlock && !floatBox.needsLayout() && | 
| view()->layoutState()->pageLogicalHeightChanged()) | 
| @@ -3345,9 +3500,9 @@ void LayoutBlockFlow::removeFloatingObject(LayoutBox* floatBox) { | 
| logicalTop == LayoutUnit::max()) { | 
| logicalBottom = LayoutUnit::max(); | 
| } else { | 
| -          // Special-case zero- and less-than-zero-height floats: those don't touch | 
| -          // the line that they're on, but it still needs to be dirtied. This is | 
| -          // accomplished by pretending they have a height of 1. | 
| +          // Special-case zero- and less-than-zero-height floats: those don't | 
| +          // touch the line that they're on, but it still needs to be dirtied. | 
| +          // This is accomplished by pretending they have a height of 1. | 
| logicalBottom = std::max(logicalBottom, logicalTop + 1); | 
| } | 
| if (floatingObject.originatingLine()) { | 
| @@ -3396,9 +3551,9 @@ bool LayoutBlockFlow::positionNewFloats(LineWidth* width) { | 
| if (floatingObjectSet.last()->isPlaced()) | 
| return false; | 
|  | 
| -  // Move backwards through our floating object list until we find a float that has | 
| -  // already been positioned. Then we'll be able to move forward, positioning all of | 
| -  // the new floats that need it. | 
| +  // Move backwards through our floating object list until we find a float that | 
| +  // has already been positioned. Then we'll be able to move forward, | 
| +  // positioning all of the new floats that need it. | 
| FloatingObjectSetIterator it = floatingObjectSet.end(); | 
| --it;  // Go to last item. | 
| FloatingObjectSetIterator begin = floatingObjectSet.begin(); | 
| @@ -3423,8 +3578,9 @@ bool LayoutBlockFlow::positionNewFloats(LineWidth* width) { | 
| // Now walk through the set of unpositioned floats and place them. | 
| for (; it != end; ++it) { | 
| FloatingObject& floatingObject = *it->get(); | 
| -    // The containing block is responsible for positioning floats, so if we have floats in our | 
| -    // list that come from somewhere else, do not attempt to position them. | 
| +    // The containing block is responsible for positioning floats, so if we have | 
| +    // floats in our list that come from somewhere else, do not attempt to | 
| +    // position them. | 
| if (floatingObject.layoutObject()->containingBlock() != this) | 
| continue; | 
|  | 
| @@ -3445,8 +3601,8 @@ bool LayoutBlockFlow::positionNewFloats(LineWidth* width) { | 
|  | 
| bool isPaginated = view()->layoutState()->isPaginated(); | 
| if (isPaginated && !childrenInline()) { | 
| -      // Forced breaks are inserted at class A break points. Floats may be affected by a | 
| -      // break-after value on the previous in-flow sibling. | 
| +      // Forced breaks are inserted at class A break points. Floats may be | 
| +      // affected by a break-after value on the previous in-flow sibling. | 
| if (LayoutBox* previousInFlowBox = childBox->previousInFlowSiblingBox()) | 
| logicalTop = | 
| applyForcedBreak(logicalTop, previousInFlowBox->breakAfter()); | 
| @@ -3471,13 +3627,14 @@ bool LayoutBlockFlow::positionNewFloats(LineWidth* width) { | 
| if (isPaginated) { | 
| LayoutBlockFlow* childBlockFlow = | 
| childBox->isLayoutBlockFlow() ? toLayoutBlockFlow(childBox) : nullptr; | 
| -      // The first piece of content inside the child may have set a strut during layout. | 
| +      // The first piece of content inside the child may have set a strut during | 
| +      // layout. | 
| LayoutUnit strut = | 
| childBlockFlow ? childBlockFlow->paginationStrutPropagatedFromChild() | 
| : LayoutUnit(); | 
| if (!strut) { | 
| -        // Otherwise, if we are unsplittable and don't fit, move to the next page or column | 
| -        // if that helps the situation. | 
| +        // Otherwise, if we are unsplittable and don't fit, move to the next | 
| +        // page or column if that helps the situation. | 
| strut = | 
| adjustForUnsplittableChild(*childBox, floatLogicalLocation.y()) - | 
| floatLogicalLocation.y(); | 
| @@ -3536,11 +3693,13 @@ void LayoutBlockFlow::addIntrudingFloats(LayoutBlockFlow* prev, | 
| LayoutUnit logicalTopOffset) { | 
| ASSERT(!avoidsFloats()); | 
|  | 
| -  // If we create our own block formatting context then our contents don't interact with floats outside it, even those from our parent. | 
| +  // If we create our own block formatting context then our contents don't | 
| +  // interact with floats outside it, even those from our parent. | 
| if (createsNewFormattingContext()) | 
| return; | 
|  | 
| -  // If the parent or previous sibling doesn't have any floats to add, don't bother. | 
| +  // If the parent or previous sibling doesn't have any floats to add, don't | 
| +  // bother. | 
| if (!prev->m_floatingObjects) | 
| return; | 
|  | 
| @@ -3558,11 +3717,12 @@ void LayoutBlockFlow::addIntrudingFloats(LayoutBlockFlow* prev, | 
| if (!m_floatingObjects) | 
| createFloatingObjects(); | 
|  | 
| -        // Applying the child's margin makes no sense in the case where the child was passed in. | 
| -        // since this margin was added already through the modification of the |logicalLeftOffset| variable | 
| -        // above. |logicalLeftOffset| will equal the margin in this case, so it's already been taken | 
| -        // into account. Only apply this code if prev is the parent, since otherwise the left margin | 
| -        // will get applied twice. | 
| +        // Applying the child's margin makes no sense in the case where the | 
| +        // child was passed in since this margin was added already through the | 
| +        // modification of the |logicalLeftOffset| variable above. | 
| +        // |logicalLeftOffset| will equal the margin in this case, so it's | 
| +        // already been taken into account. Only apply this code if prev is the | 
| +        // parent, since otherwise the left margin will get applied twice. | 
| LayoutSize offset = | 
| isHorizontalWritingMode() | 
| ? LayoutSize( | 
| @@ -3582,15 +3742,16 @@ void LayoutBlockFlow::addIntrudingFloats(LayoutBlockFlow* prev, | 
|  | 
| void LayoutBlockFlow::addOverhangingFloats(LayoutBlockFlow* child, | 
| bool makeChildPaintOtherFloats) { | 
| -  // Prevent floats from being added to the canvas by the root element, e.g., <html>. | 
| +  // Prevent floats from being added to the canvas by the root element, e.g., | 
| +  // <html>. | 
| if (!child->containsFloats() || child->createsNewFormattingContext()) | 
| return; | 
|  | 
| LayoutUnit childLogicalTop = child->logicalTop(); | 
| LayoutUnit childLogicalLeft = child->logicalLeft(); | 
|  | 
| -  // Floats that will remain the child's responsibility to paint should factor into its | 
| -  // overflow. | 
| +  // Floats that will remain the child's responsibility to paint should factor | 
| +  // into its overflow. | 
| FloatingObjectSetIterator childEnd = child->m_floatingObjects->set().end(); | 
| for (FloatingObjectSetIterator childIt = | 
| child->m_floatingObjects->set().begin(); | 
| @@ -3610,10 +3771,11 @@ void LayoutBlockFlow::addOverhangingFloats(LayoutBlockFlow* child, | 
| : LayoutSize(-childLogicalTop, -childLogicalLeft); | 
| bool shouldPaint = false; | 
|  | 
| -        // The nearest enclosing layer always paints the float (so that zindex and stacking | 
| -        // behaves properly). We always want to propagate the desire to paint the float as | 
| -        // far out as we can, to the outermost block that overlaps the float, stopping only | 
| -        // if we hit a self-painting layer boundary. | 
| +        // The nearest enclosing layer always paints the float (so that zindex | 
| +        // and stacking behaves properly). We always want to propagate the | 
| +        // desire to paint the float as far out as we can, to the outermost | 
| +        // block that overlaps the float, stopping only if we hit a | 
| +        // self-painting layer boundary. | 
| if (floatingObject.layoutObject()->enclosingFloatPaintingLayer() == | 
| enclosingFloatPaintingLayer() && | 
| !floatingObject.isLowestNonOverhangingFloatInChild()) { | 
| @@ -3634,16 +3796,17 @@ void LayoutBlockFlow::addOverhangingFloats(LayoutBlockFlow* child, | 
| floatingObject.layoutObject()->isDescendantOf(child) && | 
| floatingObject.layoutObject()->enclosingFloatPaintingLayer() == | 
| child->enclosingFloatPaintingLayer()) { | 
| -        // The float is not overhanging from this block, so if it is a descendant of the child, the child should | 
| -        // paint it (the other case is that it is intruding into the child), unless it has its own layer or enclosing | 
| -        // layer. | 
| -        // If makeChildPaintOtherFloats is false, it means that the child must already know about all the floats | 
| -        // it should paint. | 
| +        // The float is not overhanging from this block, so if it is a | 
| +        // descendant of the child, the child should paint it (the other case is | 
| +        // that it is intruding into the child), unless it has its own layer or | 
| +        // enclosing layer. | 
| +        // If makeChildPaintOtherFloats is false, it means that the child must | 
| +        // already know about all the floats it should paint. | 
| floatingObject.setShouldPaint(true); | 
| } | 
|  | 
| -      // Since the float doesn't overhang, it didn't get put into our list. We need to go ahead and add its overflow in to the | 
| -      // child now. | 
| +      // Since the float doesn't overhang, it didn't get put into our list. We | 
| +      // need to go ahead and add its overflow in to the child now. | 
| if (floatingObject.isDescendant()) | 
| child->addOverflowFromChild( | 
| floatingObject.layoutObject(), | 
| @@ -3806,10 +3969,12 @@ void LayoutBlockFlow::setAncestorShouldPaintFloatingObject( | 
|  | 
| FloatingObject& floatingObject = **it; | 
| if (!floatBoxIsSelfPaintingLayer) { | 
| -      // This repeats the logic in addOverhangingFloats() about shouldPaint flag: | 
| -      // - The nearest enclosing block in which the float doesn't overhang paints the float; | 
| -      // - Or even if the float overhangs, if the ancestor block has self-painting layer, it | 
| -      //   paints the float. | 
| +      // This repeats the logic in addOverhangingFloats() about shouldPaint | 
| +      // flag: | 
| +      // - The nearest enclosing block in which the float doesn't overhang | 
| +      //   paints the float; | 
| +      // - Or even if the float overhangs, if the ancestor block has | 
| +      //   self-painting layer, it paints the float. | 
| if (ancestorBlock->hasSelfPaintingLayer() || | 
| !ancestorBlock->isOverhangingFloat(floatingObject)) { | 
| floatingObject.setShouldPaint(true); | 
| @@ -3822,21 +3987,23 @@ void LayoutBlockFlow::setAncestorShouldPaintFloatingObject( | 
| } | 
|  | 
| bool LayoutBlockFlow::allowsPaginationStrut() const { | 
| -  // The block needs to be contained by a LayoutBlockFlow (and not by e.g. a flexbox, grid, or a | 
| -  // table (the latter being the case for table cell or table caption)). The reason for this | 
| -  // limitation is simply that LayoutBlockFlow child layout code is the only place where we pick | 
| -  // up the struts and handle them. We handle floats and regular in-flow children, and that's | 
| -  // all. We could handle this in other layout modes as well (and even for out-of-flow children), | 
| -  // but currently we don't. | 
| +  // The block needs to be contained by a LayoutBlockFlow (and not by e.g. a | 
| +  // flexbox, grid, or a table (the latter being the case for table cell or | 
| +  // table caption)). The reason for this limitation is simply that | 
| +  // LayoutBlockFlow child layout code is the only place where we pick up the | 
| +  // struts and handle them. We handle floats and regular in-flow children, and | 
| +  // that's all. We could handle this in other layout modes as well (and even | 
| +  // for out-of-flow children), but currently we don't. | 
| // TODO(mstensho): But we *should*. | 
| if (isOutOfFlowPositioned()) | 
| return false; | 
| if (isLayoutFlowThread()) { | 
| // Don't let the strut escape the fragmentation context and get lost. | 
| -    // TODO(mstensho): If we're in a nested fragmentation context, we should ideally convert | 
| -    // and propagate the strut to the outer fragmentation context, so that the inner one is | 
| -    // fully pushed to the next outer fragmentainer, instead of taking up unusable space in the | 
| -    // previous one. But currently we have no mechanism in place to handle this. | 
| +    // TODO(mstensho): If we're in a nested fragmentation context, we should | 
| +    // ideally convert and propagate the strut to the outer fragmentation | 
| +    // context, so that the inner one is fully pushed to the next outer | 
| +    // fragmentainer, instead of taking up unusable space in the previous one. | 
| +    // But currently we have no mechanism in place to handle this. | 
| return false; | 
| } | 
| LayoutBlock* containingBlock = this->containingBlock(); | 
| @@ -3856,15 +4023,17 @@ void LayoutBlockFlow::setPaginationStrutPropagatedFromChild(LayoutUnit strut) { | 
| void LayoutBlockFlow::positionSpannerDescendant( | 
| LayoutMultiColumnSpannerPlaceholder& child) { | 
| LayoutBox& spanner = *child.layoutObjectInFlowThread(); | 
| -  // FIXME: |spanner| is a descendant, but never a direct child, so the names here are bad, if | 
| -  // nothing else. | 
| +  // FIXME: |spanner| is a descendant, but never a direct child, so the names | 
| +  // here are bad, if nothing else. | 
| setLogicalTopForChild(spanner, child.logicalTop()); | 
| determineLogicalLeftPositionForChild(spanner); | 
| } | 
|  | 
| bool LayoutBlockFlow::avoidsFloats() const { | 
| -  // Floats can't intrude into our box if we have a non-auto column count or width. | 
| -  // Note: we need to use LayoutBox::avoidsFloats here since LayoutBlock::avoidsFloats is always true. | 
| +  // Floats can't intrude into our box if we have a non-auto column count or | 
| +  // width. | 
| +  // Note: we need to use LayoutBox::avoidsFloats here since | 
| +  // LayoutBlock::avoidsFloats is always true. | 
| return LayoutBox::avoidsFloats() || !style()->hasAutoColumnCount() || | 
| !style()->hasAutoColumnWidth(); | 
| } | 
| @@ -3946,18 +4115,20 @@ LayoutMultiColumnFlowThread* LayoutBlockFlow::createMultiColumnFlowThread( | 
|  | 
| void LayoutBlockFlow::createOrDestroyMultiColumnFlowThreadIfNeeded( | 
| const ComputedStyle* oldStyle) { | 
| -  // Paged overflow trumps multicol in this implementation. Ideally, it should be possible to have | 
| -  // both paged overflow and multicol on the same element, but then we need two flow | 
| -  // threads. Anyway, this is nothing to worry about until we can actually nest multicol properly | 
| -  // inside other fragmentation contexts. | 
| +  // Paged overflow trumps multicol in this implementation. Ideally, it should | 
| +  // be possible to have both paged overflow and multicol on the same element, | 
| +  // but then we need two flow threads. Anyway, this is nothing to worry about | 
| +  // until we can actually nest multicol properly inside other fragmentation | 
| +  // contexts. | 
| FlowThreadType type = getFlowThreadType(styleRef()); | 
|  | 
| if (multiColumnFlowThread()) { | 
| ASSERT(oldStyle); | 
| if (type != getFlowThreadType(*oldStyle)) { | 
| -      // If we're no longer to be multicol/paged, destroy the flow thread. Also destroy it | 
| -      // when switching between multicol and paged, since that affects the column set | 
| -      // structure (multicol containers may have spanners, paged containers may not). | 
| +      // If we're no longer to be multicol/paged, destroy the flow thread. Also | 
| +      // destroy it when switching between multicol and paged, since that | 
| +      // affects the column set structure (multicol containers may have | 
| +      // spanners, paged containers may not). | 
| multiColumnFlowThread()->evacuateAndDestroy(); | 
| ASSERT(!multiColumnFlowThread()); | 
| } | 
| @@ -3966,19 +4137,22 @@ void LayoutBlockFlow::createOrDestroyMultiColumnFlowThreadIfNeeded( | 
| if (type == NoFlowThread || multiColumnFlowThread()) | 
| return; | 
|  | 
| -  // Ruby elements manage child insertion in a special way, and would mess up insertion of the | 
| -  // flow thread. The flow thread needs to be a direct child of the multicol block (|this|). | 
| +  // Ruby elements manage child insertion in a special way, and would mess up | 
| +  // insertion of the flow thread. The flow thread needs to be a direct child of | 
| +  // the multicol block (|this|). | 
| if (isRuby()) | 
| return; | 
|  | 
| -  // Form controls are replaced content, and are therefore not supposed to support multicol. | 
| +  // Form controls are replaced content, and are therefore not supposed to | 
| +  // support multicol. | 
| if (isFileUploadControl() || isTextControl() || isListBox()) | 
| return; | 
|  | 
| LayoutMultiColumnFlowThread* flowThread = createMultiColumnFlowThread(type); | 
| addChild(flowThread); | 
|  | 
| -  // Check that addChild() put the flow thread as a direct child, and didn't do fancy things. | 
| +  // Check that addChild() put the flow thread as a direct child, and didn't do | 
| +  // fancy things. | 
| ASSERT(flowThread->parent() == this); | 
|  | 
| flowThread->populate(); | 
| @@ -4046,7 +4220,8 @@ void LayoutBlockFlow::simplifiedNormalFlowInlineLayout() { | 
| } | 
| } | 
|  | 
| -  // FIXME: Glyph overflow will get lost in this case, but not really a big deal. | 
| +  // FIXME: Glyph overflow will get lost in this case, but not really a big | 
| +  // deal. | 
| GlyphOverflowAndFallbackFontsMap textBoxDataMap; | 
| for (ListHashSet<RootInlineBox*>::const_iterator it = lineBoxes.begin(); | 
| it != lineBoxes.end(); ++it) { | 
| @@ -4070,7 +4245,8 @@ bool LayoutBlockFlow::recalcInlineChildrenOverflowAfterStyleChange() { | 
| } | 
| } | 
|  | 
| -  // FIXME: Glyph overflow will get lost in this case, but not really a big deal. | 
| +  // FIXME: Glyph overflow will get lost in this case, but not really a big | 
| +  // deal. | 
| GlyphOverflowAndFallbackFontsMap textBoxDataMap; | 
| for (ListHashSet<RootInlineBox*>::const_iterator it = lineBoxes.begin(); | 
| it != lineBoxes.end(); ++it) { | 
| @@ -4104,7 +4280,8 @@ PositionWithAffinity LayoutBlockFlow::positionForPoint( | 
| bool linesAreFlipped = style()->isFlippedLinesWritingMode(); | 
| bool blocksAreFlipped = style()->isFlippedBlocksWritingMode(); | 
|  | 
| -  // look for the closest line box in the root box which is at the passed-in y coordinate | 
| +  // look for the closest line box in the root box which is at the passed-in y | 
| +  // coordinate | 
| InlineBox* closestBox = nullptr; | 
| RootInlineBox* firstRootBoxWithChildren = nullptr; | 
| RootInlineBox* lastRootBoxWithChildren = nullptr; | 
| @@ -4175,7 +4352,8 @@ PositionWithAffinity LayoutBlockFlow::positionForPoint( | 
| if (InlineBox* newBox = box->nextLeafChildIgnoringLineBreak()) | 
| box = newBox; | 
| } | 
| -        // y coordinate is above first root line box, so return the start of the first | 
| +        // y coordinate is above first root line box, so return the start of the | 
| +        // first | 
| return PositionWithAffinity(positionForBox(box, true)); | 
| } | 
| } | 
| @@ -4192,7 +4370,8 @@ PositionWithAffinity LayoutBlockFlow::positionForPoint( | 
| } | 
|  | 
| if (lastRootBoxWithChildren) { | 
| -    // We hit this case for Mac behavior when the Y coordinate is below the last box. | 
| +    // We hit this case for Mac behavior when the Y coordinate is below the last | 
| +    // box. | 
| ASSERT(moveCaretToBoundary); | 
| InlineBox* logicallyLastBox; | 
| if (lastRootBoxWithChildren->getLogicalEndBoxWithNode(logicallyLastBox)) | 
| @@ -4225,15 +4404,16 @@ void LayoutBlockFlow::addOutlineRects( | 
| Vector<LayoutRect>& rects, | 
| const LayoutPoint& additionalOffset, | 
| IncludeBlockVisualOverflowOrNot includeBlockOverflows) const { | 
| -  // For blocks inside inlines, we go ahead and include margins so that we run right up to the | 
| -  // inline boxes above and below us (thus getting merged with them to form a single irregular | 
| -  // shape). | 
| +  // For blocks inside inlines, we go ahead and include margins so that we run | 
| +  // right up to the inline boxes above and below us (thus getting merged with | 
| +  // them to form a single irregular shape). | 
| const LayoutInline* inlineElementContinuation = | 
| this->inlineElementContinuation(); | 
| if (inlineElementContinuation) { | 
| // FIXME: This check really isn't accurate. | 
| bool nextInlineHasLineBox = inlineElementContinuation->firstLineBox(); | 
| -    // FIXME: This is wrong. The principal layoutObject may not be the continuation preceding this block. | 
| +    // FIXME: This is wrong. The principal layoutObject may not be the | 
| +    // continuation preceding this block. | 
| // FIXME: This is wrong for vertical writing-modes. | 
| // https://bugs.webkit.org/show_bug.cgi?id=46781 | 
| bool prevInlineHasLineBox = | 
|  |