[Layout API] Add LocalFrame::contentLayoutItem and use in VisualViewport

third_party/WebKit/Source/core/frame/VisualViewport.cpp

 /*
  * Copyright (C) 2013 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 377 matching lines @@
 }
 
 void VisualViewport::registerLayersWithTreeView(WebLayerTreeView* layerTreeView) const
 {
     TRACE_EVENT0("blink", "VisualViewport::registerLayersWithTreeView");
     ASSERT(layerTreeView);
 
     if (!mainFrame())
         return;
 
-    ASSERT(frameHost().page().deprecatedLocalMainFrame()->contentLayoutObject());
+    ASSERT(!frameHost().page().deprecatedLocalMainFrame()->contentLayoutItem().isNull());
 
-    PaintLayerCompositor* compositor = frameHost().page().deprecatedLocalMainFrame()->contentLayoutObject()->compositor();
+    PaintLayerCompositor* compositor = frameHost().page().deprecatedLocalMainFrame()->contentLayoutItem().compositor();
     // Get the outer viewport scroll layer.
     WebLayer* scrollLayer = compositor->scrollLayer() ? compositor->scrollLayer()->platformLayer() : 0;
 
     m_webOverlayScrollbarHorizontal->setScrollLayer(scrollLayer);
     m_webOverlayScrollbarVertical->setScrollLayer(scrollLayer);
 
     ASSERT(compositor);
     layerTreeView->registerViewportLayers(
         m_overscrollElasticityLayer->platformLayer(),
         m_pageScaleLayer->platformLayer(),
@@ skipping 332 matching lines @@
     } else if (graphicsLayer == m_rootTransformLayer) {
         name =  "Root Transform Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace blink