Make InlineBox::renderer() and related subclass methods return reference.

Source/core/rendering/RenderObject.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google 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 1200 matching lines @@
     void setShouldRepaintOverflowIfNeeded(bool b) { m_bitfields.setShouldRepaintOverflowIfNeeded(b); }
 
 private:
     // Store state between styleWillChange and styleDidChange
     static bool s_affectsParentBlock;
 
     LayoutRect m_oldRepaintRect;
     LayoutRect m_newRepaintRect;
 };
 
+// Allow equality comparisons of RenderObject's by reference or pointer, interchangeably.
+inline bool operator==(const RenderObject& a, const RenderObject& b) { return &a == &b; }
+inline bool operator==(const RenderObject& a, const RenderObject* b) { return &a == b; }
+inline bool operator==(const RenderObject* a, const RenderObject& b) { return a == &b; }
+inline bool operator!=(const RenderObject& a, const RenderObject& b) { return !(a == b); }
+inline bool operator!=(const RenderObject& a, const RenderObject* b) { return !(a == b); }
+inline bool operator!=(const RenderObject* a, const RenderObject& b) { return !(a == b); }
+
 inline bool RenderObject::documentBeingDestroyed() const
 {
     return !document().renderer();
 }
 
 inline bool RenderObject::isBeforeContent() const
 {
     if (style()->styleType() != BEFORE)
         return false;
     // Text nodes don't have their own styles, so ignore the style on a text node.
@@ skipping 180 matching lines @@
 void showTree(const WebCore::RenderObject*);
 void showLineTree(const WebCore::RenderObject*);
 void showRenderTree(const WebCore::RenderObject* object1);
 // We don't make object2 an optional parameter so that showRenderTree
 // can be called from gdb easily.
 void showRenderTree(const WebCore::RenderObject* object1, const WebCore::RenderObject* object2);
 
 #endif
 
 #endif // RenderObject_h