Assume FrameView::m_frame is never NULL

Source/core/page/scrolling/ScrollingCoordinator.cpp

 /*
  * Copyright (C) 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 693 matching lines @@
     return scrollableArea->layerForVerticalScrollbar();
 }
 
 bool ScrollingCoordinator::isForMainFrame(ScrollableArea* scrollableArea) const
 {
     return scrollableArea == m_page->mainFrame()->view();
 }
 
 GraphicsLayer* ScrollingCoordinator::scrollLayerForFrameView(FrameView* frameView)
 {
-    Frame* frame = frameView->frame();
-    if (!frame)
-        return 0;
-
-    RenderView* renderView = frame->contentRenderer();
+    RenderView* renderView = frameView->frame()->contentRenderer();
     if (!renderView)
         return 0;
     return renderView->compositor()->scrollLayer();
 }
 
 GraphicsLayer* ScrollingCoordinator::counterScrollingLayerForFrameView(FrameView*)
 {
     return 0;
 }
 
@@ skipping 83 matching lines @@
         stringBuilder.resize(stringBuilder.length() - 2);
     return stringBuilder.toString();
 }
 
 String ScrollingCoordinator::mainThreadScrollingReasonsAsText() const
 {
     return mainThreadScrollingReasonsAsText(mainThreadScrollingReasons());
 }
 
 } // namespace WebCore