Remove assumption that null containerForRepaint assumes RenderView

Source/core/rendering/RenderView.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2006 Apple Computer, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 125 matching lines @@
     }
 
     bool shouldDisableLayoutStateForSubtree(RenderObject&) const;
 
     // Returns true if layoutState should be used for its cached offset and clip.
     bool layoutStateEnabled() const { return m_layoutStateDisableCount == 0 && m_layoutState; }
     LayoutState* layoutState() const { return m_layoutState; }
 
     bool canUseLayoutStateForContainer(const RenderObject* repaintContainer) const
     {
-        // FIXME: Repaint container should never be null. crbug.com/363699
         // FIXME: LayoutState should be enabled for other repaint containers than the RenderView. crbug.com/363834
-        return layoutStateEnabled() && (!repaintContainer || repaintContainer == this);
+        return layoutStateEnabled() && (repaintContainer == this);
     }
 
     virtual void updateHitTestResult(HitTestResult&, const LayoutPoint&) OVERRIDE;
 
     LayoutUnit pageLogicalHeight() const { return m_pageLogicalHeight; }
     void setPageLogicalHeight(LayoutUnit height)
     {
         if (m_pageLogicalHeight != height) {
             m_pageLogicalHeight = height;
             m_pageLogicalHeightChanged = true;
@@ skipping 215 matching lines @@
     {
         m_view.enableLayoutState();
     }
 private:
     RenderView& m_view;
 };
 
 } // namespace WebCore
 
 #endif // RenderView_h