Change PaintLayer::m_layoutObject to a reference.

third_party/WebKit/Source/core/layout/compositing/GraphicsLayerTreeBuilder.cpp

 /*
  * Copyright (C) 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 22 matching lines @@
 #include "core/layout/compositing/PaintLayerCompositor.h"
 #include "core/paint/PaintLayer.h"
 
 namespace blink {
 
 GraphicsLayerTreeBuilder::GraphicsLayerTreeBuilder() {}
 
 GraphicsLayerTreeBuilder::~GraphicsLayerTreeBuilder() {}
 
 static bool shouldAppendLayer(const PaintLayer& layer) {
-  Node* node = layer.layoutObject()->node();
+  Node* node = layer.layoutObject().node();
   if (node && isHTMLVideoElement(*node)) {
     HTMLVideoElement* element = toHTMLVideoElement(node);
     if (element->isFullscreen() && element->usesOverlayFullscreenVideo())
       return false;
   }
   return true;
 }
 
 void GraphicsLayerTreeBuilder::rebuild(PaintLayer& layer,
                                        GraphicsLayerVector& childLayers) {
@@ skipping 33 matching lines @@
           currentCompositedLayerMapping->foregroundLayer());
   }
 
   PaintLayerStackingNodeIterator iterator(
       *layer.stackingNode(), NormalFlowChildren | PositiveZOrderChildren);
   while (PaintLayerStackingNode* curNode = iterator.next())
     rebuild(*curNode->layer(), *layerVectorForChildren);
 
   if (hasCompositedLayerMapping) {
     bool parented = false;
-    if (layer.layoutObject()->isLayoutPart())
+    if (layer.layoutObject().isLayoutPart())
       parented = PaintLayerCompositor::attachFrameContentLayersToIframeLayer(
           toLayoutPart(layer.layoutObject()));
 
     if (!parented)
       currentCompositedLayerMapping->setSublayers(thisLayerChildren);
 
     if (shouldAppendLayer(layer))
       childLayers.push_back(
           currentCompositedLayerMapping->childForSuperlayers());
   }
 
   if (layer.scrollParent() &&
       layer.scrollParent()->hasCompositedLayerMapping() &&
       layer.scrollParent()
           ->compositedLayerMapping()
           ->needsToReparentOverflowControls() &&
       layer.scrollParent()->getScrollableArea()->topmostScrollChild() ==
           &layer) {
     childLayers.push_back(layer.scrollParent()
                               ->compositedLayerMapping()
                               ->detachLayerForOverflowControls());
   }
 }
 
 }  // namespace blink