*** DO NOT LAND *** Attempt to understand Regions complexity

Source/core/rendering/RenderLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 47 matching lines @@
 #include "core/page/Page.h"
 #include "core/frame/Settings.h"
 #include "core/frame/animation/AnimationController.h"
 #include "core/page/scrolling/ScrollingCoordinator.h"
 #include "core/rendering/ColumnInfo.h"
 #include "core/rendering/CompositedLayerMapping.h"
 #include "core/rendering/FilterEffectRenderer.h"
 #include "core/rendering/HitTestRequest.h"
 #include "core/rendering/HitTestResult.h"
 #include "core/rendering/HitTestingTransformState.h"
-#include "core/rendering/RenderFlowThread.h"
 #include "core/rendering/RenderGeometryMap.h"
 #include "core/rendering/RenderInline.h"
 #include "core/rendering/RenderLayerCompositor.h"
 #include "core/rendering/RenderReplica.h"
 #include "core/rendering/RenderScrollbar.h"
 #include "core/rendering/RenderScrollbarPart.h"
 #include "core/rendering/RenderTreeAsText.h"
 #include "core/rendering/RenderView.h"
 #include "core/rendering/svg/ReferenceFilterBuilder.h"
 #include "core/rendering/svg/RenderSVGResourceClipper.h"
@@ skipping 201 matching lines @@
 
     // Go ahead and update the reflection's position and size.
     if (m_reflectionInfo)
         m_reflectionInfo->reflection()->layout();
 
     // Clear the IsCompositingUpdateRoot flag once we've found the first compositing layer in this update.
     bool isUpdateRoot = (flags & IsCompositingUpdateRoot);
     if (hasCompositedLayerMapping())
         flags &= ~IsCompositingUpdateRoot;
 
-    if (useRegionBasedColumns() && renderer()->isInFlowRenderFlowThread()) {
-        updatePagination();
-        flags |= UpdatePagination;
-    }
-
     if (renderer()->hasColumns())
         flags |= UpdatePagination;
 
     for (RenderLayer* child = firstChild(); child; child = child->nextSibling())
         child->updateLayerPositions(geometryMap, flags);
 
     if ((flags & UpdateCompositingLayers) && hasCompositedLayerMapping()) {
         CompositedLayerMapping::UpdateAfterLayoutFlags updateFlags = CompositedLayerMapping::CompositingChildrenOnly;
         if (flags & NeedsFullRepaintInBacking)
             updateFlags |= CompositedLayerMapping::NeedsFullRepaint;
@@ skipping 286 matching lines @@
         return false;
 
     // If the previous block is absolutely positioned, then we can't be paginated by the columns block.
     if (prevBlock->isOutOfFlowPositioned())
         return false;
 
     // Otherwise we are paginated by the columns block.
     return true;
 }
 
-bool RenderLayer::useRegionBasedColumns() const
-{
-    const Settings* settings = renderer()->document().settings();
-    return settings && settings->regionBasedColumnsEnabled();
-}
-
 void RenderLayer::updatePagination()
 {
     m_isPaginated = false;
     m_enclosingPaginationLayer = 0;
 
     if (hasCompositedLayerMapping() || !parent())
         return; // FIXME: We will have to deal with paginated compositing layers someday.
                 // FIXME: For now the RenderView can't be paginated.  Eventually printing will move to a model where it is though.
 
-    // The main difference between the paginated booleans for the old column code and the new column code
-    // is that each paginated layer has to paint on its own with the new code. There is no
-    // recurring into child layers. This means that the m_isPaginated bits for the new column code can't just be set on
-    // "roots" that get split and paint all their descendants. Instead each layer has to be checked individually and
-    // genuinely know if it is going to have to split itself up when painting only its contents (and not any other descendant
-    // layers). We track an enclosingPaginationLayer instead of using a simple bit, since we want to be able to get back
-    // to that layer easily.
-    bool regionBasedColumnsUsed = useRegionBasedColumns();
-    if (regionBasedColumnsUsed && renderer()->isInFlowRenderFlowThread()) {
-        m_enclosingPaginationLayer = this;
+    if (m_stackingNode->isNormalFlowOnly()) {
+        m_isPaginated = parent()->renderer()->hasColumns();
         return;
     }
 
-    if (m_stackingNode->isNormalFlowOnly()) {
-        if (regionBasedColumnsUsed) {
-            // Content inside a transform is not considered to be paginated, since we simply
-            // paint the transform multiple times in each column, so we don't have to use
-            // fragments for the transformed content.
-            m_enclosingPaginationLayer = parent()->enclosingPaginationLayer();
-            if (m_enclosingPaginationLayer && m_enclosingPaginationLayer->hasTransform())
-                m_enclosingPaginationLayer = 0;
-        } else
-            m_isPaginated = parent()->renderer()->hasColumns();
-        return;
-    }
-
-    // For the new columns code, we want to walk up our containing block chain looking for an enclosing layer. Once
-    // we find one, then we just check its pagination status.
-    if (regionBasedColumnsUsed) {
-        RenderView* view = renderer()->view();
-        RenderBlock* containingBlock;
-        for (containingBlock = renderer()->containingBlock();
-             containingBlock && containingBlock != view;
-             containingBlock = containingBlock->containingBlock()) {
-            if (containingBlock->hasLayer()) {
-                // Content inside a transform is not considered to be paginated, since we simply
-                // paint the transform multiple times in each column, so we don't have to use
-                // fragments for the transformed content.
-                m_enclosingPaginationLayer = containingBlock->layer()->enclosingPaginationLayer();
-                if (m_enclosingPaginationLayer && m_enclosingPaginationLayer->hasTransform())
-                    m_enclosingPaginationLayer = 0;
-                return;
-            }
-        }
-        return;
-    }
-
     // If we're not normal flow, then we need to look for a multi-column object between us and our stacking container.
     RenderLayerStackingNode* ancestorStackingContainerNode = m_stackingNode->ancestorStackingContainerNode();
     for (RenderLayer* curr = parent(); curr; curr = curr->parent()) {
         if (curr->renderer()->hasColumns()) {
             m_isPaginated = checkContainingBlockChainForPagination(renderer(), curr->renderBox());
             return;
         }
         if (curr->stackingNode() == ancestorStackingContainerNode)
             return;
     }
@@ skipping 567 matching lines @@
 
         // We don't use fragment boxes when collecting a transformed layer's bounding box, since it always
         // paints unfragmented.
         LayoutRect clipRect = layer->boundingBox(layer);
         expandClipRectForDescendantsAndReflection(clipRect, layer, layer, transparencyBehavior, paintBehavior);
         layer->renderer()->style()->filterOutsets().expandRect(clipRect);
         LayoutRect result = transform.mapRect(clipRect);
         if (!paginationLayer)
             return result;
 
-        // We have to break up the transformed extent across our columns.
-        // Split our box up into the actual fragment boxes that render in the columns/pages and unite those together to
-        // get our true bounding box.
-        RenderFlowThread* enclosingFlowThread = toRenderFlowThread(paginationLayer->renderer());
-        result = enclosingFlowThread->fragmentsBoundingBox(result);
-
         LayoutPoint rootLayerDelta;
         paginationLayer->convertToLayerCoords(rootLayer, rootLayerDelta);
         result.moveBy(rootLayerDelta);
         return result;
     }
 
     LayoutRect clipRect = layer->boundingBox(rootLayer, RenderLayer::UseFragmentBoxes);
     expandClipRectForDescendantsAndReflection(clipRect, layer, rootLayer, transparencyBehavior, paintBehavior);
     layer->renderer()->style()->filterOutsets().expandRect(clipRect);
     return clipRect;
@@ skipping 217 matching lines @@
 }
 
 // Returns the layer reached on the walk up towards the ancestor.
 static inline const RenderLayer* accumulateOffsetTowardsAncestor(const RenderLayer* layer, const RenderLayer* ancestorLayer, LayoutPoint& location)
 {
     ASSERT(ancestorLayer != layer);
 
     const RenderLayerModelObject* renderer = layer->renderer();
     EPosition position = renderer->style()->position();
 
-    // FIXME: Special casing RenderFlowThread so much for fixed positioning here is not great.
-    RenderFlowThread* fixedFlowThreadContainer = position == FixedPosition ? renderer->flowThreadContainingBlock() : 0;
-    if (fixedFlowThreadContainer && !fixedFlowThreadContainer->isOutOfFlowPositioned())
-        fixedFlowThreadContainer = 0;
-
-    // FIXME: Positioning of out-of-flow(fixed, absolute) elements collected in a RenderFlowThread
-    // may need to be revisited in a future patch.
-    // If the fixed renderer is inside a RenderFlowThread, we should not compute location using localToAbsolute,
-    // since localToAbsolute maps the coordinates from named flow to regions coordinates and regions can be
-    // positioned in a completely different place in the viewport (RenderView).
-    if (position == FixedPosition && !fixedFlowThreadContainer && (!ancestorLayer || ancestorLayer == renderer->view()->layer())) {
+    if (position == FixedPosition && (!ancestorLayer || ancestorLayer == renderer->view()->layer())) {
         // If the fixed layer's container is the root, just add in the offset of the view. We can obtain this by calling
         // localToAbsolute() on the RenderView.
         FloatPoint absPos = renderer->localToAbsolute(FloatPoint(), IsFixed);
         location += LayoutSize(absPos.x(), absPos.y());
         return ancestorLayer;
     }
 
-    // For the fixed positioned elements inside a render flow thread, we should also skip the code path below
-    // Otherwise, for the case of ancestorLayer == rootLayer and fixed positioned element child of a transformed
-    // element in render flow thread, we will hit the fixed positioned container before hitting the ancestor layer.
-    if (position == FixedPosition && !fixedFlowThreadContainer) {
+    if (position == FixedPosition) {
         // For a fixed layers, we need to walk up to the root to see if there's a fixed position container
         // (e.g. a transformed layer). It's an error to call convertToLayerCoords() across a layer with a transform,
         // so we should always find the ancestor at or before we find the fixed position container.
         RenderLayer* fixedPositionContainerLayer = 0;
         bool foundAncestor = false;
         for (RenderLayer* currLayer = layer->parent(); currLayer; currLayer = currLayer->parent()) {
             if (currLayer == ancestorLayer)
                 foundAncestor = true;
 
             if (isFixedPositionedContainer(currLayer)) {
@@ skipping 32 matching lines @@
                 break;
 
             if (parentLayer == ancestorLayer) {
                 foundAncestorFirst = true;
                 break;
             }
 
             parentLayer = parentLayer->parent();
         }
 
-        // We should not reach RenderView layer past the RenderFlowThread layer for any
-        // children of the RenderFlowThread.
-        if (renderer->flowThreadContainingBlock() && !layer->isOutOfFlowRenderFlowThread())
-            ASSERT(parentLayer != renderer->view()->layer());
-
         if (foundAncestorFirst) {
             // Found ancestorLayer before the abs. positioned container, so compute offset of both relative
             // to enclosingPositionedAncestor and subtract.
             RenderLayer* positionedAncestor = parentLayer->enclosingPositionedAncestor();
 
             LayoutPoint thisCoords;
             layer->convertToLayerCoords(positionedAncestor, thisCoords);
 
             LayoutPoint ancestorCoords;
             ancestorLayer->convertToLayerCoords(positionedAncestor, ancestorCoords);
@@ skipping 126 matching lines @@
     if (hasCompositedLayerMapping())
         return compositedLayerMapping()->collectTrackedRepaintRects();
     return nullptr;
 }
 
 bool RenderLayer::hasOverflowControls() const
 {
     return m_scrollableArea && (m_scrollableArea->hasScrollbar() || m_scrollableArea->hasScrollCorner() || renderer()->style()->resize() != RESIZE_NONE);
 }
 
-void RenderLayer::paint(GraphicsContext* context, const LayoutRect& damageRect, PaintBehavior paintBehavior, RenderObject* paintingRoot, RenderRegion* region, PaintLayerFlags paintFlags)
+void RenderLayer::paint(GraphicsContext* context, const LayoutRect& damageRect, PaintBehavior paintBehavior, RenderObject* paintingRoot, PaintLayerFlags paintFlags)
 {
     OverlapTestRequestMap overlapTestRequests;
 
-    LayerPaintingInfo paintingInfo(this, enclosingIntRect(damageRect), paintBehavior, LayoutSize(), paintingRoot, region, &overlapTestRequests);
+    LayerPaintingInfo paintingInfo(this, enclosingIntRect(damageRect), paintBehavior, LayoutSize(), paintingRoot, &overlapTestRequests);
     paintLayer(context, paintingInfo, paintFlags);
 
     OverlapTestRequestMap::iterator end = overlapTestRequests.end();
     for (OverlapTestRequestMap::iterator it = overlapTestRequests.begin(); it != end; ++it)
         it->key->setIsOverlapped(false);
 }
 
 void RenderLayer::paintOverlayScrollbars(GraphicsContext* context, const LayoutRect& damageRect, PaintBehavior paintBehavior, RenderObject* paintingRoot)
 {
     if (!m_containsDirtyOverlayScrollbars)
@@ skipping 139 matching lines @@
         }
 
         if (enclosingPaginationLayer()) {
             paintTransformedLayerIntoFragments(context, paintingInfo, paintFlags);
             return;
         }
 
         // Make sure the parent's clip rects have been calculated.
         ClipRect clipRect = paintingInfo.paintDirtyRect;
         if (parent()) {
-            ClipRectsContext clipRectsContext(paintingInfo.rootLayer, paintingInfo.region, (paintFlags & PaintLayerTemporaryClipRects) ? TemporaryClipRects : PaintingClipRects,
+            ClipRectsContext clipRectsContext(paintingInfo.rootLayer, (paintFlags & PaintLayerTemporaryClipRects) ? TemporaryClipRects : PaintingClipRects,
                 IgnoreOverlayScrollbarSize, (paintFlags & PaintLayerPaintingOverflowContents) ? IgnoreOverflowClip : RespectOverflowClip);
             clipRect = clipper().backgroundClipRect(clipRectsContext);
             clipRect.intersect(paintingInfo.paintDirtyRect);
 
             // Push the parent coordinate space's clip.
             parent()->clipToRect(paintingInfo.rootLayer, context, paintingInfo.paintDirtyRect, clipRect);
         }
 
         paintLayerByApplyingTransform(context, paintingInfo, paintFlags);
 
@@ skipping 172 matching lines @@
     PaintBehavior paintBehavior = PaintBehaviorNormal;
     if (paintFlags & PaintLayerPaintingSkipRootBackground)
         paintBehavior |= PaintBehaviorSkipRootBackground;
     else if (paintFlags & PaintLayerPaintingRootBackgroundOnly)
         paintBehavior |= PaintBehaviorRootBackgroundOnly;
 
     LayerFragments layerFragments;
     if (shouldPaintContent || shouldPaintOutline || isPaintingOverlayScrollbars) {
         // Collect the fragments. This will compute the clip rectangles and paint offsets for each layer fragment, as well as whether or not the content of each
         // fragment should paint.
-        collectFragments(layerFragments, localPaintingInfo.rootLayer, localPaintingInfo.region, localPaintingInfo.paintDirtyRect,
+        collectFragments(layerFragments, localPaintingInfo.rootLayer, localPaintingInfo.paintDirtyRect,
             (paintFlags & PaintLayerTemporaryClipRects) ? TemporaryClipRects : PaintingClipRects, IgnoreOverlayScrollbarSize,
             (isPaintingOverflowContents) ? IgnoreOverflowClip : RespectOverflowClip, &offsetFromRoot, localPaintingInfo.subPixelAccumulation);
         updatePaintingInfoForFragments(layerFragments, localPaintingInfo, paintFlags, shouldPaintContent, &offsetFromRoot);
     }
 
     if (shouldPaintBackground)
         paintBackgroundForFragments(layerFragments, context, transparencyLayerContext, paintingInfo.paintDirtyRect, haveTransparency,
                 localPaintingInfo, paintBehavior, paintingRootForRenderer);
 
     if (shouldPaintNegZOrderList)
@@ skipping 57 matching lines @@
     IntPoint roundedDelta = roundedIntPoint(delta);
     transform.translateRight(roundedDelta.x(), roundedDelta.y());
     LayoutSize adjustedSubPixelAccumulation = paintingInfo.subPixelAccumulation + (delta - roundedDelta);
 
     // Apply the transform.
     GraphicsContextStateSaver stateSaver(*context);
     context->concatCTM(transform.toAffineTransform());
 
     // Now do a paint with the root layer shifted to be us.
     LayerPaintingInfo transformedPaintingInfo(this, enclosingIntRect(transform.inverse().mapRect(paintingInfo.paintDirtyRect)), paintingInfo.paintBehavior,
-        adjustedSubPixelAccumulation, paintingInfo.paintingRoot, paintingInfo.region, paintingInfo.overlapTestRequests);
+        adjustedSubPixelAccumulation, paintingInfo.paintingRoot, paintingInfo.overlapTestRequests);
     paintLayerContentsAndReflection(context, transformedPaintingInfo, paintFlags);
 }
 
 void RenderLayer::paintChildren(unsigned childrenToVisit, GraphicsContext* context, const LayerPaintingInfo& paintingInfo, PaintLayerFlags paintFlags)
 {
     if (!hasSelfPaintingLayerDescendant())
         return;
 
 #if !ASSERT_DISABLED
     LayerListMutationDetector mutationChecker(m_stackingNode.get());
 #endif
 
     RenderLayerStackingNodeIterator iterator(*m_stackingNode, childrenToVisit);
     while (RenderLayerStackingNode* child = iterator.next()) {
         RenderLayer* childLayer = child->layer();
 
         // Squashed RenderLayers should not paint into their ancestor.
         if (childLayer->compositingState() == PaintsIntoGroupedBacking)
             continue;
 
         if (!childLayer->isPaginated())
             childLayer->paintLayer(context, paintingInfo, paintFlags);
         else
             paintPaginatedChildLayer(childLayer, context, paintingInfo, paintFlags);
     }
 }
 
-void RenderLayer::collectFragments(LayerFragments& fragments, const RenderLayer* rootLayer, RenderRegion* region, const LayoutRect& dirtyRect,
+void RenderLayer::collectFragments(LayerFragments& fragments, const RenderLayer* rootLayer, const LayoutRect& dirtyRect,
     ClipRectsType clipRectsType, OverlayScrollbarSizeRelevancy inOverlayScrollbarSizeRelevancy, ShouldRespectOverflowClip respectOverflowClip, const LayoutPoint* offsetFromRoot,
     const LayoutSize& subPixelAccumulation, const LayoutRect* layerBoundingBox)
 {
     if (!enclosingPaginationLayer() || hasTransform()) {
         // For unpaginated layers, there is only one fragment.
         LayerFragment fragment;
-        ClipRectsContext clipRectsContext(rootLayer, region, clipRectsType, inOverlayScrollbarSizeRelevancy, respectOverflowClip, subPixelAccumulation);
+        ClipRectsContext clipRectsContext(rootLayer, clipRectsType, inOverlayScrollbarSizeRelevancy, respectOverflowClip, subPixelAccumulation);
         clipper().calculateRects(clipRectsContext, dirtyRect, fragment.layerBounds, fragment.backgroundRect, fragment.foregroundRect, fragment.outlineRect, offsetFromRoot);
         fragments.append(fragment);
         return;
     }
 
     // Compute our offset within the enclosing pagination layer.
     LayoutPoint offsetWithinPaginatedLayer;
     convertToLayerCoords(enclosingPaginationLayer(), offsetWithinPaginatedLayer);
 
     // Calculate clip rects relative to the enclosingPaginationLayer. The purpose of this call is to determine our bounds clipped to intermediate
     // layers between us and the pagination context. It's important to minimize the number of fragments we need to create and this helps with that.
-    ClipRectsContext paginationClipRectsContext(enclosingPaginationLayer(), region, clipRectsType, inOverlayScrollbarSizeRelevancy, respectOverflowClip);
+    ClipRectsContext paginationClipRectsContext(enclosingPaginationLayer(), clipRectsType, inOverlayScrollbarSizeRelevancy, respectOverflowClip);
     LayoutRect layerBoundsInFlowThread;
     ClipRect backgroundRectInFlowThread;
     ClipRect foregroundRectInFlowThread;
     ClipRect outlineRectInFlowThread;
     clipper().calculateRects(paginationClipRectsContext, PaintInfo::infiniteRect(), layerBoundsInFlowThread, backgroundRectInFlowThread, foregroundRectInFlowThread,
         outlineRectInFlowThread, &offsetWithinPaginatedLayer);
 
     // Take our bounding box within the flow thread and clip it.
     LayoutRect layerBoundingBoxInFlowThread = layerBoundingBox ? *layerBoundingBox : boundingBox(enclosingPaginationLayer(), 0, &offsetWithinPaginatedLayer);
     layerBoundingBoxInFlowThread.intersect(backgroundRectInFlowThread.rect());
 
     // Shift the dirty rect into flow thread coordinates.
     LayoutPoint offsetOfPaginationLayerFromRoot;
     enclosingPaginationLayer()->convertToLayerCoords(rootLayer, offsetOfPaginationLayerFromRoot);
     LayoutRect dirtyRectInFlowThread(dirtyRect);
     dirtyRectInFlowThread.moveBy(-offsetOfPaginationLayerFromRoot);
-
-    // Tell the flow thread to collect the fragments. We pass enough information to create a minimal number of fragments based off the pages/columns
-    // that intersect the actual dirtyRect as well as the pages/columns that intersect our layer's bounding box.
-    RenderFlowThread* enclosingFlowThread = toRenderFlowThread(enclosingPaginationLayer()->renderer());
-    enclosingFlowThread->collectLayerFragments(fragments, layerBoundingBoxInFlowThread, dirtyRectInFlowThread);
-
-    if (fragments.isEmpty())
-        return;
-
-    // Get the parent clip rects of the pagination layer, since we need to intersect with that when painting column contents.
-    ClipRect ancestorClipRect = dirtyRect;
-    if (enclosingPaginationLayer()->parent()) {
-        ClipRectsContext clipRectsContext(rootLayer, region, clipRectsType, inOverlayScrollbarSizeRelevancy, respectOverflowClip);
-        ancestorClipRect = enclosingPaginationLayer()->clipper().backgroundClipRect(clipRectsContext);
-        ancestorClipRect.intersect(dirtyRect);
-    }
-
-    for (size_t i = 0; i < fragments.size(); ++i) {
-        LayerFragment& fragment = fragments.at(i);
-
-        // Set our four rects with all clipping applied that was internal to the flow thread.
-        fragment.setRects(layerBoundsInFlowThread, backgroundRectInFlowThread, foregroundRectInFlowThread, outlineRectInFlowThread);
-
-        // Shift to the root-relative physical position used when painting the flow thread in this fragment.
-        fragment.moveBy(fragment.paginationOffset + offsetOfPaginationLayerFromRoot);
-
-        // Intersect the fragment with our ancestor's background clip so that e.g., columns in an overflow:hidden block are
-        // properly clipped by the overflow.
-        fragment.intersect(ancestorClipRect.rect());
-
-        // Now intersect with our pagination clip. This will typically mean we're just intersecting the dirty rect with the column
-        // clip, so the column clip ends up being all we apply.
-        fragment.intersect(fragment.paginationClip);
-    }
 }
 
 void RenderLayer::updatePaintingInfoForFragments(LayerFragments& fragments, const LayerPaintingInfo& localPaintingInfo, PaintLayerFlags localPaintFlags,
     bool shouldPaintContent, const LayoutPoint* offsetFromRoot)
 {
     ASSERT(offsetFromRoot);
     for (size_t i = 0; i < fragments.size(); ++i) {
         LayerFragment& fragment = fragments.at(i);
         fragment.shouldPaintContent = shouldPaintContent;
         if (this != localPaintingInfo.rootLayer || !(localPaintFlags & PaintLayerPaintingOverflowContents)) {
             LayoutPoint newOffsetFromRoot = *offsetFromRoot + fragment.paginationOffset;
             fragment.shouldPaintContent &= intersectsDamageRect(fragment.layerBounds, fragment.backgroundRect.rect(), localPaintingInfo.rootLayer, &newOffsetFromRoot);
         }
     }
 }
 
 void RenderLayer::paintTransformedLayerIntoFragments(GraphicsContext* context, const LayerPaintingInfo& paintingInfo, PaintLayerFlags paintFlags)
 {
     LayerFragments enclosingPaginationFragments;
     LayoutPoint offsetOfPaginationLayerFromRoot;
     LayoutRect transformedExtent = transparencyClipBox(this, enclosingPaginationLayer(), PaintingTransparencyClipBox, RootOfTransparencyClipBox, paintingInfo.paintBehavior);
-    enclosingPaginationLayer()->collectFragments(enclosingPaginationFragments, paintingInfo.rootLayer, paintingInfo.region, paintingInfo.paintDirtyRect,
+    enclosingPaginationLayer()->collectFragments(enclosingPaginationFragments, paintingInfo.rootLayer, paintingInfo.paintDirtyRect,
         (paintFlags & PaintLayerTemporaryClipRects) ? TemporaryClipRects : PaintingClipRects, IgnoreOverlayScrollbarSize,
         (paintFlags & PaintLayerPaintingOverflowContents) ? IgnoreOverflowClip : RespectOverflowClip, &offsetOfPaginationLayerFromRoot, paintingInfo.subPixelAccumulation, &transformedExtent);
 
     for (size_t i = 0; i < enclosingPaginationFragments.size(); ++i) {
         const LayerFragment& fragment = enclosingPaginationFragments.at(i);
 
         // Apply the page/column clip for this fragment, as well as any clips established by layers in between us and
         // the enclosing pagination layer.
         LayoutRect clipRect = fragment.backgroundRect.rect();
 
         // Now compute the clips within a given fragment
         if (parent() != enclosingPaginationLayer()) {
             enclosingPaginationLayer()->convertToLayerCoords(paintingInfo.rootLayer, offsetOfPaginationLayerFromRoot);
 
-            ClipRectsContext clipRectsContext(enclosingPaginationLayer(), paintingInfo.region, (paintFlags & PaintLayerTemporaryClipRects) ? TemporaryClipRects : PaintingClipRects,
+            ClipRectsContext clipRectsContext(enclosingPaginationLayer(), (paintFlags & PaintLayerTemporaryClipRects) ? TemporaryClipRects : PaintingClipRects,
                 IgnoreOverlayScrollbarSize, (paintFlags & PaintLayerPaintingOverflowContents) ? IgnoreOverflowClip : RespectOverflowClip);
             LayoutRect parentClipRect = clipper().backgroundClipRect(clipRectsContext).rect();
             parentClipRect.moveBy(fragment.paginationOffset + offsetOfPaginationLayerFromRoot);
             clipRect.intersect(parentClipRect);
         }
 
         parent()->clipToRect(paintingInfo.rootLayer, context, paintingInfo.paintDirtyRect, clipRect);
         paintLayerByApplyingTransform(context, paintingInfo, paintFlags, fragment.paginationOffset);
         parent()->restoreClip(context, paintingInfo.paintDirtyRect, clipRect);
     }
@@ skipping 22 matching lines @@
             beginTransparencyLayers(transparencyLayerContext, localPaintingInfo.rootLayer, transparencyPaintDirtyRect, localPaintingInfo.paintBehavior);
 
         if (localPaintingInfo.clipToDirtyRect) {
             // Paint our background first, before painting any child layers.
             // Establish the clip used to paint our background.
             clipToRect(localPaintingInfo.rootLayer, context, localPaintingInfo.paintDirtyRect, fragment.backgroundRect, DoNotIncludeSelfForBorderRadius); // Background painting will handle clipping to self.
         }
 
         // Paint the background.
         // FIXME: Eventually we will collect the region from the fragment itself instead of just from the paint info.
-        PaintInfo paintInfo(context, pixelSnappedIntRect(fragment.backgroundRect.rect()), PaintPhaseBlockBackground, paintBehavior, paintingRootForRenderer, localPaintingInfo.region, 0, 0, localPaintingInfo.rootLayer->renderer());
+        PaintInfo paintInfo(context, pixelSnappedIntRect(fragment.backgroundRect.rect()), PaintPhaseBlockBackground, paintBehavior, paintingRootForRenderer, 0, 0, localPaintingInfo.rootLayer->renderer());
         renderer()->paint(paintInfo, toPoint(fragment.layerBounds.location() - renderBoxLocation() + subPixelAccumulationIfNeeded(localPaintingInfo.subPixelAccumulation, compositingState())));
 
         if (localPaintingInfo.clipToDirtyRect)
             restoreClip(context, localPaintingInfo.paintDirtyRect, fragment.backgroundRect);
     }
 }
 
 void RenderLayer::paintForegroundForFragments(const LayerFragments& layerFragments, GraphicsContext* context, GraphicsContext* transparencyLayerContext,
     const LayoutRect& transparencyPaintDirtyRect, bool haveTransparency, const LayerPaintingInfo& localPaintingInfo, PaintBehavior paintBehavior,
     RenderObject* paintingRootForRenderer, bool selectionOnly, bool forceBlackText)
@@ skipping 37 matching lines @@
     bool shouldClip = localPaintingInfo.clipToDirtyRect && layerFragments.size() > 1;
 
     for (size_t i = 0; i < layerFragments.size(); ++i) {
         const LayerFragment& fragment = layerFragments.at(i);
         if (!fragment.shouldPaintContent || fragment.foregroundRect.isEmpty())
             continue;
 
         if (shouldClip)
             clipToRect(localPaintingInfo.rootLayer, context, localPaintingInfo.paintDirtyRect, fragment.foregroundRect);
 
-        PaintInfo paintInfo(context, pixelSnappedIntRect(fragment.foregroundRect.rect()), phase, paintBehavior, paintingRootForRenderer, localPaintingInfo.region, 0, 0, localPaintingInfo.rootLayer->renderer());
+        PaintInfo paintInfo(context, pixelSnappedIntRect(fragment.foregroundRect.rect()), phase, paintBehavior, paintingRootForRenderer, 0, 0, localPaintingInfo.rootLayer->renderer());
         if (phase == PaintPhaseForeground)
             paintInfo.overlapTestRequests = localPaintingInfo.overlapTestRequests;
         renderer()->paint(paintInfo, toPoint(fragment.layerBounds.location() - renderBoxLocation() + subPixelAccumulationIfNeeded(localPaintingInfo.subPixelAccumulation, compositingState())));
 
         if (shouldClip)
             restoreClip(context, localPaintingInfo.paintDirtyRect, fragment.foregroundRect);
     }
 }
 
 void RenderLayer::paintOutlineForFragments(const LayerFragments& layerFragments, GraphicsContext* context, const LayerPaintingInfo& localPaintingInfo,
     PaintBehavior paintBehavior, RenderObject* paintingRootForRenderer)
 {
     for (size_t i = 0; i < layerFragments.size(); ++i) {
         const LayerFragment& fragment = layerFragments.at(i);
         if (fragment.outlineRect.isEmpty())
             continue;
 
         // Paint our own outline
-        PaintInfo paintInfo(context, pixelSnappedIntRect(fragment.outlineRect.rect()), PaintPhaseSelfOutline, paintBehavior, paintingRootForRenderer, localPaintingInfo.region, 0, 0, localPaintingInfo.rootLayer->renderer());
+        PaintInfo paintInfo(context, pixelSnappedIntRect(fragment.outlineRect.rect()), PaintPhaseSelfOutline, paintBehavior, paintingRootForRenderer, 0, 0, localPaintingInfo.rootLayer->renderer());
         clipToRect(localPaintingInfo.rootLayer, context, localPaintingInfo.paintDirtyRect, fragment.outlineRect, DoNotIncludeSelfForBorderRadius);
         renderer()->paint(paintInfo, toPoint(fragment.layerBounds.location() - renderBoxLocation() + subPixelAccumulationIfNeeded(localPaintingInfo.subPixelAccumulation, compositingState())));
         restoreClip(context, localPaintingInfo.paintDirtyRect, fragment.outlineRect);
     }
 }
 
 void RenderLayer::paintMaskForFragments(const LayerFragments& layerFragments, GraphicsContext* context, const LayerPaintingInfo& localPaintingInfo,
     RenderObject* paintingRootForRenderer)
 {
     for (size_t i = 0; i < layerFragments.size(); ++i) {
         const LayerFragment& fragment = layerFragments.at(i);
         if (!fragment.shouldPaintContent)
             continue;
 
         if (localPaintingInfo.clipToDirtyRect)
             clipToRect(localPaintingInfo.rootLayer, context, localPaintingInfo.paintDirtyRect, fragment.backgroundRect, DoNotIncludeSelfForBorderRadius); // Mask painting will handle clipping to self.
 
         // Paint the mask.
         // FIXME: Eventually we will collect the region from the fragment itself instead of just from the paint info.
-        PaintInfo paintInfo(context, pixelSnappedIntRect(fragment.backgroundRect.rect()), PaintPhaseMask, PaintBehaviorNormal, paintingRootForRenderer, localPaintingInfo.region, 0, 0, localPaintingInfo.rootLayer->renderer());
+        PaintInfo paintInfo(context, pixelSnappedIntRect(fragment.backgroundRect.rect()), PaintPhaseMask, PaintBehaviorNormal, paintingRootForRenderer, 0, 0, localPaintingInfo.rootLayer->renderer());
         renderer()->paint(paintInfo, toPoint(fragment.layerBounds.location() - renderBoxLocation() + subPixelAccumulationIfNeeded(localPaintingInfo.subPixelAccumulation, compositingState())));
 
         if (localPaintingInfo.clipToDirtyRect)
             restoreClip(context, localPaintingInfo.paintDirtyRect, fragment.backgroundRect);
     }
 }
 
 void RenderLayer::paintChildClippingMaskForFragments(const LayerFragments& layerFragments, GraphicsContext* context, const LayerPaintingInfo& localPaintingInfo,
     RenderObject* paintingRootForRenderer)
 {
     for (size_t i = 0; i < layerFragments.size(); ++i) {
         const LayerFragment& fragment = layerFragments.at(i);
         if (!fragment.shouldPaintContent)
             continue;
 
         if (localPaintingInfo.clipToDirtyRect)
             clipToRect(localPaintingInfo.rootLayer, context, localPaintingInfo.paintDirtyRect, fragment.foregroundRect, IncludeSelfForBorderRadius); // Child clipping mask painting will handle clipping to self.
 
         // Paint the the clipped mask.
-        PaintInfo paintInfo(context, pixelSnappedIntRect(fragment.backgroundRect.rect()), PaintPhaseClippingMask, PaintBehaviorNormal, paintingRootForRenderer, localPaintingInfo.region, 0, 0, localPaintingInfo.rootLayer->renderer());
+        PaintInfo paintInfo(context, pixelSnappedIntRect(fragment.backgroundRect.rect()), PaintPhaseClippingMask, PaintBehaviorNormal, paintingRootForRenderer, 0, 0, localPaintingInfo.rootLayer->renderer());
         renderer()->paint(paintInfo, toPoint(fragment.layerBounds.location() - renderBoxLocation() + subPixelAccumulationIfNeeded(localPaintingInfo.subPixelAccumulation, compositingState())));
 
         if (localPaintingInfo.clipToDirtyRect)
             restoreClip(context, localPaintingInfo.paintDirtyRect, fragment.foregroundRect);
     }
 }
 
 void RenderLayer::paintOverflowControlsForFragments(const LayerFragments& layerFragments, GraphicsContext* context, const LayerPaintingInfo& localPaintingInfo)
 {
     for (size_t i = 0; i < layerFragments.size(); ++i) {
@@ skipping 137 matching lines @@
 }
 
 bool RenderLayer::hitTest(const HitTestRequest& request, const HitTestLocation& hitTestLocation, HitTestResult& result)
 {
     ASSERT(isSelfPaintingLayer() || hasSelfPaintingLayerDescendant());
 
     // RenderView should make sure to update layout before entering hit testing
     ASSERT(!renderer()->frame()->view()->layoutPending());
     ASSERT(!renderer()->document().renderer()->needsLayout());
 
-    LayoutRect hitTestArea = isOutOfFlowRenderFlowThread() ? toRenderFlowThread(renderer())->borderBoxRect() : renderer()->view()->documentRect();
+    LayoutRect hitTestArea = renderer()->view()->documentRect();
     if (!request.ignoreClipping())
         hitTestArea.intersect(frameVisibleRect(renderer()));
 
     RenderLayer* insideLayer = hitTestLayer(this, 0, request, result, hitTestArea, hitTestLocation, false);
     if (!insideLayer) {
         // We didn't hit any layer. If we are the root layer and the mouse is -- or just was -- down,
         // return ourselves. We do this so mouse events continue getting delivered after a drag has
         // exited the WebView, and so hit testing over a scrollbar hits the content document.
         if (!request.isChildFrameHitTest() && (request.active() || request.release()) && isRootLayer()) {
             renderer()->updateHitTestResult(result, toRenderView(renderer())->flipForWritingMode(hitTestLocation.point()));
@@ skipping 126 matching lines @@
 
     // The natural thing would be to keep HitTestingTransformState on the stack, but it's big, so we heap-allocate.
 
     // Apply a transform if we have one.
     if (transform() && !appliedTransform) {
         if (enclosingPaginationLayer())
             return hitTestTransformedLayerInFragments(rootLayer, containerLayer, request, result, hitTestRect, hitTestLocation, transformState, zOffset);
 
         // Make sure the parent's clip rects have been calculated.
         if (parent()) {
-            ClipRectsContext clipRectsContext(rootLayer, hitTestLocation.region(), RootRelativeClipRects, IncludeOverlayScrollbarSize);
+            ClipRectsContext clipRectsContext(rootLayer, RootRelativeClipRects, IncludeOverlayScrollbarSize);
             ClipRect clipRect = clipper().backgroundClipRect(clipRectsContext);
             // Go ahead and test the enclosing clip now.
             if (!clipRect.intersects(hitTestLocation))
                 return 0;
         }
 
         return hitTestLayerByApplyingTransform(rootLayer, containerLayer, request, result, hitTestRect, hitTestLocation, transformState, zOffset);
     }
 
     // Ensure our lists and 3d status are up-to-date.
@@ skipping 65 matching lines @@
     hitLayer = hitTestChildren(NormalFlowChildren, rootLayer, request, result, hitTestRect, hitTestLocation,
                            localTransformState.get(), zOffsetForDescendantsPtr, zOffset, unflattenedTransformState.get(), depthSortDescendants);
     if (hitLayer) {
         if (!depthSortDescendants)
             return hitLayer;
         candidateLayer = hitLayer;
     }
 
     // Collect the fragments. This will compute the clip rectangles for each layer fragment.
     LayerFragments layerFragments;
-    collectFragments(layerFragments, rootLayer, hitTestLocation.region(), hitTestRect, RootRelativeClipRects, IncludeOverlayScrollbarSize);
+    collectFragments(layerFragments, rootLayer, hitTestRect, RootRelativeClipRects, IncludeOverlayScrollbarSize);
 
     if (m_scrollableArea && m_scrollableArea->hitTestResizerInFragments(layerFragments, hitTestLocation)) {
         renderer()->updateHitTestResult(result, hitTestLocation.point());
         return this;
     }
 
     // Next we want to see if the mouse pos is inside the child RenderObjects of the layer. Check
     // every fragment in reverse order.
     if (isSelfPaintingLayer()) {
         // Hit test with a temporary HitTestResult, because we only want to commit to 'result' if we know we're frontmost.
@@ skipping 62 matching lines @@
 
     return false;
 }
 
 RenderLayer* RenderLayer::hitTestTransformedLayerInFragments(RenderLayer* rootLayer, RenderLayer* containerLayer, const HitTestRequest& request, HitTestResult& result,
     const LayoutRect& hitTestRect, const HitTestLocation& hitTestLocation, const HitTestingTransformState* transformState, double* zOffset)
 {
     LayerFragments enclosingPaginationFragments;
     LayoutPoint offsetOfPaginationLayerFromRoot;
     LayoutRect transformedExtent = transparencyClipBox(this, enclosingPaginationLayer(), HitTestingTransparencyClipBox, RootOfTransparencyClipBox);
-    enclosingPaginationLayer()->collectFragments(enclosingPaginationFragments, rootLayer, hitTestLocation.region(), hitTestRect,
+    enclosingPaginationLayer()->collectFragments(enclosingPaginationFragments, rootLayer, hitTestRect,
         RootRelativeClipRects, IncludeOverlayScrollbarSize, RespectOverflowClip, &offsetOfPaginationLayerFromRoot, LayoutSize(), &transformedExtent);
 
     for (int i = enclosingPaginationFragments.size() - 1; i >= 0; --i) {
         const LayerFragment& fragment = enclosingPaginationFragments.at(i);
 
         // Apply the page/column clip for this fragment, as well as any clips established by layers in between us and
         // the enclosing pagination layer.
         LayoutRect clipRect = fragment.backgroundRect.rect();
 
         // Now compute the clips within a given fragment
         if (parent() != enclosingPaginationLayer()) {
             enclosingPaginationLayer()->convertToLayerCoords(rootLayer, offsetOfPaginationLayerFromRoot);
 
-            ClipRectsContext clipRectsContext(enclosingPaginationLayer(), hitTestLocation.region(), RootRelativeClipRects, IncludeOverlayScrollbarSize);
+            ClipRectsContext clipRectsContext(enclosingPaginationLayer(), RootRelativeClipRects, IncludeOverlayScrollbarSize);
             LayoutRect parentClipRect = clipper().backgroundClipRect(clipRectsContext).rect();
             parentClipRect.moveBy(fragment.paginationOffset + offsetOfPaginationLayerFromRoot);
             clipRect.intersect(parentClipRect);
         }
 
         if (!hitTestLocation.intersects(clipRect))
             continue;
 
         RenderLayer* hitLayer = hitTestLayerByApplyingTransform(rootLayer, containerLayer, request, result, hitTestRect, hitTestLocation,
             transformState, zOffset, fragment.paginationOffset);
@@ skipping 237 matching lines @@
         child->repaintBlockSelectionGaps();
 
     if (m_blockSelectionGapsBounds.isEmpty())
         return;
 
     LayoutRect rect = m_blockSelectionGapsBounds;
     if (renderer()->hasOverflowClip()) {
         RenderBox* box = renderBox();
         rect.move(-box->scrolledContentOffset());
         if (!scrollableArea()->usesCompositedScrolling())
-            rect.intersect(box->overflowClipRect(LayoutPoint(), 0)); // FIXME: Regions not accounted for.
+            rect.intersect(box->overflowClipRect(LayoutPoint()));
     }
     if (renderer()->hasClip())
-        rect.intersect(toRenderBox(renderer())->clipRect(LayoutPoint(), 0)); // FIXME: Regions not accounted for.
+        rect.intersect(toRenderBox(renderer())->clipRect(LayoutPoint()));
     if (!rect.isEmpty())
         renderer()->repaintRectangle(rect);
 }
 
 bool RenderLayer::hasBlockSelectionGapBounds() const
 {
     return !m_blockSelectionGapsBounds.isEmpty();
 }
 
 bool RenderLayer::intersectsDamageRect(const LayoutRect& layerBounds, const LayoutRect& damageRect, const RenderLayer* rootLayer, const LayoutPoint* offsetFromRoot) const
@@ skipping 69 matching lines @@
 }
 
 LayoutRect RenderLayer::boundingBox(const RenderLayer* ancestorLayer, CalculateLayerBoundsFlags flags, const LayoutPoint* offsetFromRoot) const
 {
     LayoutRect result = localBoundingBox(flags);
     if (renderer()->isBox())
         renderBox()->flipForWritingMode(result);
     else
         renderer()->containingBlock()->flipForWritingMode(result);
 
-    if (enclosingPaginationLayer() && (flags & UseFragmentBoxes)) {
-        // Split our box up into the actual fragment boxes that render in the columns/pages and unite those together to
-        // get our true bounding box.
-        LayoutPoint offsetWithinPaginationLayer;
-        convertToLayerCoords(enclosingPaginationLayer(), offsetWithinPaginationLayer);
-        result.moveBy(offsetWithinPaginationLayer);
-
-        RenderFlowThread* enclosingFlowThread = toRenderFlowThread(enclosingPaginationLayer()->renderer());
-        result = enclosingFlowThread->fragmentsBoundingBox(result);
-
-        LayoutPoint delta;
-        if (offsetFromRoot)
-            delta = *offsetFromRoot;
-        else
-            enclosingPaginationLayer()->convertToLayerCoords(ancestorLayer, delta);
-        result.moveBy(delta);
-        return result;
-    }
-
     LayoutPoint delta;
     if (offsetFromRoot)
         delta = *offsetFromRoot;
     else
         convertToLayerCoords(ancestorLayer, delta);
 
     result.moveBy(delta);
     return result;
 }
 
@@ skipping 626 matching lines @@
     }
 }
 
 void showLayerTree(const WebCore::RenderObject* renderer)
 {
     if (!renderer)
         return;
     showLayerTree(renderer->enclosingLayer());
 }
 #endif