Clean up forward declarations in core/rendering and core/painting

Source/core/rendering/RenderLineBoxList.h

 /*
  * Copyright (C) 2009 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
@@ skipping 16 matching lines @@
  */
 
 
 #ifndef RenderLineBoxList_h
 #define RenderLineBoxList_h
 
 #include "core/rendering/RenderObject.h"
 
 namespace blink {
 
+class InlineFlowBox;
 class RenderLineBoxList {
 public:
     RenderLineBoxList()
         : m_firstLineBox(0)
         , m_lastLineBox(0)
     {
     }
 
 #if ENABLE(ASSERT)
     ~RenderLineBoxList();
@@ skipping 33 matching lines @@
 
 #if !ENABLE(ASSERT)
 inline void RenderLineBoxList::checkConsistency() const
 {
 }
 #endif
 
 } // namespace blink
 
 #endif // RenderFlow_h