| Index: third_party/WebKit/Source/core/paint/BoxPaintInvalidator.cpp | 
| diff --git a/third_party/WebKit/Source/core/paint/BoxPaintInvalidator.cpp b/third_party/WebKit/Source/core/paint/BoxPaintInvalidator.cpp | 
| index e5341e50c476d2d4f318572d11a1ff6e714151db..5493a27944cb97c14560ce0faae5cec51ec3e539 100644 | 
| --- a/third_party/WebKit/Source/core/paint/BoxPaintInvalidator.cpp | 
| +++ b/third_party/WebKit/Source/core/paint/BoxPaintInvalidator.cpp | 
| @@ -44,7 +44,8 @@ bool BoxPaintInvalidator::incrementallyInvalidatePaint() { | 
| LayoutSize oldBorderBoxSize = computePreviousBorderBoxSize(oldBounds.size()); | 
| LayoutSize newBorderBoxSize = m_box.size(); | 
|  | 
| -  // If border m_box size didn't change, ObjectPaintInvalidatorWithContext::incrementallyInvalidatePaint() is good. | 
| +  // If border m_box size didn't change, | 
| +  // ObjectPaintInvalidatorWithContext::incrementallyInvalidatePaint() is good. | 
| if (oldBorderBoxSize == newBorderBoxSize) | 
| return result; | 
|  | 
| @@ -59,7 +60,8 @@ bool BoxPaintInvalidator::incrementallyInvalidatePaint() { | 
| newBorderBoxSize == newBounds.size()) | 
| return result; | 
|  | 
| -  // Invalidate the right delta part and the right border of the old or new m_box which has smaller width. | 
| +  // Invalidate the right delta part and the right border of the old or new | 
| +  // m_box which has smaller width. | 
| if (LayoutUnit deltaWidth = | 
| (oldBorderBoxSize.width() - newBorderBoxSize.width()).abs()) { | 
| LayoutUnit smallerWidth = | 
| @@ -78,7 +80,8 @@ bool BoxPaintInvalidator::incrementallyInvalidatePaint() { | 
| invalidatePaintRectClippedByOldAndNewBounds(rightDeltaRect); | 
| } | 
|  | 
| -  // Invalidate the bottom delta part and the bottom border of the old or new m_box which has smaller height. | 
| +  // Invalidate the bottom delta part and the bottom border of the old or new | 
| +  // m_box which has smaller height. | 
| if (LayoutUnit deltaHeight = | 
| (oldBorderBoxSize.height() - newBorderBoxSize.height()).abs()) { | 
| LayoutUnit smallerHeight = | 
| @@ -116,7 +119,8 @@ void BoxPaintInvalidator::invalidatePaintRectClippedByOldAndNewBounds( | 
| PaintInvalidationIncremental); | 
| return; | 
| } | 
| -  // Invalidate the bigger one if one contains another. Otherwise invalidate both. | 
| +  // Invalidate the bigger one if one contains another. Otherwise invalidate | 
| +  // both. | 
| if (!rectClippedByNewBounds.contains(rectClippedByOldBounds)) | 
| objectPaintInvalidator.invalidatePaintUsingContainer( | 
| *m_context.paintInvalidationContainer, rectClippedByOldBounds, | 
| @@ -140,9 +144,11 @@ PaintInvalidationReason BoxPaintInvalidator::computePaintInvalidationReason() { | 
| !m_box.backgroundIsKnownToBeObscured()) | 
| reason = PaintInvalidationDelayedFull; | 
|  | 
| -  // If the current paint invalidation reason is PaintInvalidationDelayedFull, then this paint invalidation can delayed if the | 
| -  // LayoutBox in question is not on-screen. The logic to decide whether this is appropriate exists at the site of the original | 
| -  // paint invalidation that chose PaintInvalidationDelayedFull. | 
| +  // If the current paint invalidation reason is PaintInvalidationDelayedFull, | 
| +  // then this paint invalidation can delayed if the LayoutBox in question is | 
| +  // not on-screen. The logic to decide whether this is appropriate exists at | 
| +  // the site of the original paint invalidation that chose | 
| +  // PaintInvalidationDelayedFull. | 
| if (reason == PaintInvalidationDelayedFull) { | 
| // Do regular full paint invalidation if the object is onscreen. | 
| return m_box.intersectsVisibleViewport() ? PaintInvalidationFull | 
| @@ -151,19 +157,22 @@ PaintInvalidationReason BoxPaintInvalidator::computePaintInvalidationReason() { | 
|  | 
| if (m_box.isLayoutView()) { | 
| const LayoutView& layoutView = toLayoutView(m_box); | 
| -    // In normal compositing mode, root background doesn't need to be invalidated for | 
| -    // box changes, because the background always covers the whole document rect | 
| -    // and clipping is done by compositor()->m_containerLayer. Also the scrollbars | 
| -    // are always composited. There are no other box decoration on the LayoutView thus | 
| -    // we can safely exit here. | 
| +    // In normal compositing mode, root background doesn't need to be | 
| +    // invalidated for box changes, because the background always covers the | 
| +    // whole document rect and clipping is done by | 
| +    // compositor()->m_containerLayer. Also the scrollbars are always | 
| +    // composited. There are no other box decoration on the LayoutView thus we | 
| +    // can safely exit here. | 
| if (layoutView.usesCompositing() && | 
| !RuntimeEnabledFeatures::rootLayerScrollingEnabled()) | 
| return reason; | 
| } | 
|  | 
| -  // If the transform is not identity or translation, incremental invalidation is not applicable | 
| -  // because the difference between oldBounds and newBounds doesn't cover all area needing invalidation. | 
| -  // FIXME: Should also consider ancestor transforms since paintInvalidationContainer. crbug.com/426111. | 
| +  // If the transform is not identity or translation, incremental invalidation | 
| +  // is not applicable because the difference between oldBounds and newBounds | 
| +  // doesn't cover all area needing invalidation. | 
| +  // FIXME: Should also consider ancestor transforms since | 
| +  // paintInvalidationContainer. crbug.com/426111. | 
| if (reason == PaintInvalidationIncremental && | 
| m_context.oldBounds != m_context.newBounds && | 
| m_context.paintInvalidationContainer != m_box && m_box.hasLayer() && | 
| @@ -181,8 +190,9 @@ PaintInvalidationReason BoxPaintInvalidator::computePaintInvalidationReason() { | 
| } | 
|  | 
| if (!style.hasBackground() && !style.hasBoxDecorations()) { | 
| -    // We could let incremental invalidation cover non-composited scrollbars, but just | 
| -    // do a full invalidation because incremental invalidation will go away with slimming paint. | 
| +    // We could let incremental invalidation cover non-composited scrollbars, | 
| +    // but just do a full invalidation because incremental invalidation will go | 
| +    // away with slimming paint. | 
| if (reason == PaintInvalidationIncremental && | 
| m_context.oldBounds != m_context.newBounds && | 
| m_box.hasNonCompositedScrollbars()) | 
| @@ -212,8 +222,8 @@ PaintInvalidationReason BoxPaintInvalidator::computePaintInvalidationReason() { | 
| return PaintInvalidationBorderBoxChange; | 
|  | 
| if (style.hasBorderRadius()) { | 
| -    // If a border-radius exists and width/height is smaller than radius width/height, | 
| -    // we need to fully invalidate to cover the changed radius. | 
| +    // If a border-radius exists and width/height is smaller than radius | 
| +    // width/height, we need to fully invalidate to cover the changed radius. | 
| FloatRoundedRect oldRoundedRect = style.getRoundedBorderFor( | 
| LayoutRect(LayoutPoint(0, 0), oldBorderBoxSize)); | 
| FloatRoundedRect newRoundedRect = style.getRoundedBorderFor( | 
| @@ -241,8 +251,9 @@ PaintInvalidationReason BoxPaintInvalidator::invalidatePaintIfNeeded() { | 
| } else { | 
| reason = PaintInvalidationNone; | 
| } | 
| -    // Though we have done our own version of incremental invalidation, we still need to call | 
| -    // ObjectPaintInvalidator with PaintInvalidationNone to do any other required operations. | 
| +    // Though we have done our own version of incremental invalidation, we still | 
| +    // need to call ObjectPaintInvalidator with PaintInvalidationNone to do any | 
| +    // other required operations. | 
| reason = std::max( | 
| reason, | 
| ObjectPaintInvalidatorWithContext(m_box, m_context) | 
| @@ -270,11 +281,13 @@ bool BoxPaintInvalidator::needsToSavePreviousBoxSizes() { | 
|  | 
| const ComputedStyle& style = m_box.styleRef(); | 
|  | 
| -  // If we use border-box sizing we need to track changes in the size of the content box. | 
| +  // If we use border-box sizing we need to track changes in the size of the | 
| +  // content box. | 
| if (style.boxSizing() == BoxSizingBorderBox) | 
| return true; | 
|  | 
| -  // We need the old box sizes only when the box has background, decorations, or masks. | 
| +  // We need the old box sizes only when the box has background, decorations, or | 
| +  // masks. | 
| // Main LayoutView paints base background, thus interested in box size. | 
| if (!m_box.isLayoutView() && !style.hasBackground() && | 
| !style.hasBoxDecorations() && !style.hasMask()) | 
| @@ -285,7 +298,8 @@ bool BoxPaintInvalidator::needsToSavePreviousBoxSizes() { | 
| if (paintInvalidationSize != m_box.size()) | 
| return true; | 
|  | 
| -  // Background and mask layers can depend on other boxes than border box. See crbug.com/490533 | 
| +  // Background and mask layers can depend on other boxes than border box. See | 
| +  // crbug.com/490533 | 
| if (style.backgroundLayers().thisOrNextLayersUseContentBox() || | 
| style.backgroundLayers().thisOrNextLayersHaveLocalAttachment() || | 
| style.maskLayers().thisOrNextLayersUseContentBox()) | 
| @@ -307,7 +321,8 @@ void BoxPaintInvalidator::savePreviousBoxSizesIfNeeded() { | 
|  | 
| LayoutSize BoxPaintInvalidator::computePreviousBorderBoxSize( | 
| const LayoutSize& previousBoundsSize) { | 
| -  // PreviousBorderBoxSize is only valid when there is background or box decorations. | 
| +  // PreviousBorderBoxSize is only valid when there is background or box | 
| +  // decorations. | 
| DCHECK(m_box.styleRef().hasBackground() || | 
| m_box.styleRef().hasBoxDecorations()); | 
|  | 
| @@ -315,7 +330,8 @@ LayoutSize BoxPaintInvalidator::computePreviousBorderBoxSize( | 
| if (it != previousBoxSizesMap().end()) | 
| return it->value.borderBoxSize; | 
|  | 
| -  // We didn't save the old border box size because it was the same as the size of oldBounds. | 
| +  // We didn't save the old border box size because it was the same as the size | 
| +  // of oldBounds. | 
| return previousBoundsSize; | 
| } | 
|  | 
|  |