content: Cleanup class/struct forward declarations

content/browser/renderer_host/render_view_host_factory.h

 // Copyright (c) 2012 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.
 
 #ifndef CONTENT_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_FACTORY_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_FACTORY_H_
 
 #include <stdint.h>
 
 #include "base/macros.h"
 #include "content/common/content_export.h"
 
 namespace content {
-class RenderFrameHostDelegate;
 class RenderViewHost;
 class RenderViewHostDelegate;
 class RenderWidgetHostDelegate;
-class SessionStorageNamespace;
 class SiteInstance;
 
 // A factory for creating RenderViewHosts. There is a global factory function
 // that can be installed for the purposes of testing to provide a specialized
 // RenderViewHost class.
 class RenderViewHostFactory {
  public:
   // Creates a RenderViewHost using the currently registered factory, or the
   // default one if no factory is registered. Ownership of the returned
   // pointer will be passed to the caller.
@@ skipping 53 matching lines @@
   // Set to true if the RenderViewHost is not a test instance. Defaults to
   // false.
   CONTENT_EXPORT static bool is_real_render_view_host_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderViewHostFactory);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_VIEW_HOST_FACTORY_H_