Cleanup: Remove more forward declarations in various chrome/browser directories.

chrome/browser/sidebar/sidebar_container.h

 // Copyright (c) 2011 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 CHROME_BROWSER_SIDEBAR_SIDEBAR_CONTAINER_H_
 #define CHROME_BROWSER_SIDEBAR_SIDEBAR_CONTAINER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/string16.h"
 #include "chrome/browser/extensions/image_loading_tracker.h"
 #include "content/browser/tab_contents/tab_contents_delegate.h"
 
-class BrowserWindow;
-class Profile;
-class RenderViewHost;
 class SkBitmap;
 class TabContents;
 
 ///////////////////////////////////////////////////////////////////////////////
 // SidebarContainer
 //
 //  Stores one particular sidebar state: sidebar's content, its content id,
 //  tab it is linked to, mini tab icon, title etc.
 //
 class SidebarContainer
@@ skipping 110 matching lines @@
   // icon should be used or discarded.
   bool use_default_icon_;
 
   // Helper to load icons from extension asynchronously.
   scoped_ptr<ImageLoadingTracker> image_loading_tracker_;
 
   DISALLOW_COPY_AND_ASSIGN(SidebarContainer);
 };
 
 #endif  // CHROME_BROWSER_SIDEBAR_SIDEBAR_CONTAINER_H_