blink: Cleanup Document.h class forward declarations

third_party/WebKit/Source/core/dom/AXObjectCache.h

 /*
  * Copyright (C) 2003, 2006, 2007, 2008, 2009, 2010, 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
@@ skipping 20 matching lines @@
 #include "core/dom/Document.h"
 #include <memory>
 
 typedef unsigned AXID;
 
 namespace blink {
 
 class AbstractInlineTextBox;
 class AXObject;
 class FrameView;
+class HTMLCanvasElement;
 class HTMLOptionElement;
 class HTMLSelectElement;
 class LayoutMenuList;
 class LineLayoutItem;
 class Page;
 
 class CORE_EXPORT AXObjectCache
     : public GarbageCollectedFinalized<AXObjectCache> {
   WTF_MAKE_NONCOPYABLE(AXObjectCache);
 
@@ skipping 123 matching lines @@
  private:
   explicit ScopedAXObjectCache(Document&);
 
   Persistent<Document> m_document;
   Persistent<AXObjectCache> m_cache;
 };
 
 }  // namespace blink
 
 #endif