Return Frame&, not Frame* from RenderView::frame()

Source/core/rendering/RenderLayerBacking.cpp

 /*
  * Copyright (C) 2009, 2010, 2011 Apple 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 141 matching lines @@
 RenderLayerBacking::RenderLayerBacking(RenderLayer* layer)
     : m_owningLayer(layer)
     , m_artificiallyInflatedBounds(false)
     , m_boundsConstrainedByClipping(false)
     , m_isMainFrameRenderViewLayer(false)
     , m_requiresOwnBackingStore(true)
     , m_canCompositeFilters(false)
     , m_backgroundLayerPaintsFixedRootBackground(false)
 {
     if (layer->isRootLayer()) {
-        Frame* frame = toRenderView(renderer())->frameView()->frame();
-        Page* page = frame ? frame->page() : 0;
-        if (page && frame && page->mainFrame() == frame) {
+        Frame& frame = toRenderView(renderer())->frameView()->frame();
+        Page* page = frame.page();
+        if (page && page->mainFrame() == &frame) {
             m_isMainFrameRenderViewLayer = true;
         }
     }
 
     createPrimaryGraphicsLayer();
 }
 
 RenderLayerBacking::~RenderLayerBacking()
 {
     updateClippingLayers(false, false);
@@ skipping 1754 matching lines @@
     } else if (graphicsLayer == m_scrollingContentsLayer.get()) {
         name = "Scrolling Contents Layer";
     } else {
         ASSERT_NOT_REACHED();
     }
 
     return name;
 }
 
 } // namespace WebCore