Assume FrameView::m_frame is never NULL

Source/core/page/FrameView.h

 /*
    Copyright (C) 1997 Martin Jones (mjones@kde.org)
              (C) 1998 Waldo Bastian (bastian@kde.org)
              (C) 1998, 1999 Torben Weis (weis@kde.org)
              (C) 1999 Lars Knoll (knoll@kde.org)
              (C) 1999 Antti Koivisto (koivisto@kde.org)
    Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
 
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
@@ skipping 56 matching lines @@
     virtual ~FrameView();
 
     virtual HostWindow* hostWindow() const;
 
     virtual void invalidateRect(const IntRect&);
     virtual void setFrameRect(const IntRect&);
 
     virtual bool scheduleAnimation();
 
     Frame* frame() const { return m_frame.get(); }
-    void clearFrame();
 
-    RenderView* renderView() const { return m_frame ? m_frame->contentRenderer() : 0; }
+    RenderView* renderView() const { return m_frame->contentRenderer(); }
 
     int mapFromLayoutToCSSUnits(LayoutUnit);
     LayoutUnit mapFromCSSToLayoutUnits(int);
 
     LayoutUnit marginWidth() const { return m_margins.width(); } // -1 means default
     LayoutUnit marginHeight() const { return m_margins.height(); } // -1 means default
     void setMarginWidth(LayoutUnit);
     void setMarginHeight(LayoutUnit);
 
     virtual void setCanHaveScrollbars(bool);
@@ skipping 487 matching lines @@
     ASSERT(!widget || widget->isFrameView());
     return static_cast<const FrameView*>(widget);
 }
 
 // This will catch anyone doing an unnecessary cast.
 void toFrameView(const FrameView*);
 
 } // namespace WebCore
 
 #endif // FrameView_h