content: Cleanup class/struct forward declarations

content/renderer/history_entry.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /*
  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  *     (http://www.torchmobile.com/)
  *
  * Redistribution and use in source and binary forms, with or without
@@ skipping 26 matching lines @@
 
 #include <memory>
 
 #include "base/containers/hash_tables.h"
 #include "base/memory/scoped_vector.h"
 #include "base/memory/weak_ptr.h"
 #include "content/common/content_export.h"
 #include "third_party/WebKit/public/platform/WebURLRequest.h"
 #include "third_party/WebKit/public/web/WebHistoryItem.h"
 
-namespace blink {
-class WebFrame;
-}
-
 namespace content {
 class RenderFrameImpl;
 class RenderViewImpl;
 
 class CONTENT_EXPORT HistoryEntry {
  public:
   class HistoryNode {
    public:
     HistoryNode(const base::WeakPtr<HistoryEntry>& entry,
                 const blink::WebHistoryItem& item);
@@ skipping 44 matching lines @@
 
   typedef base::hash_map<std::string, HistoryNode*> UniqueNamesToItems;
   UniqueNamesToItems unique_names_to_items_;
 
   base::WeakPtrFactory<HistoryEntry> weak_ptr_factory_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_HISTORY_ENTRY_H_