Remove obviously unneeded forward declarations in chrome/browser/[abef]*/*.h.

chrome/browser/extensions/extension_data_deleter.h

 // Copyright (c) 2010 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_EXTENSIONS_EXTENSION_DATA_DELETER_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_DATA_DELETER_H_
 #pragma once
 
 #include <string>
 
 #include "base/ref_counted.h"
 #include "chrome/browser/chrome_thread.h"
 #include "chrome/browser/in_process_webkit/webkit_context.h"
 #include "chrome/common/net/url_request_context_getter.h"
 #include "googleurl/src/gurl.h"
 #include "webkit/database/database_tracker.h"
 
-class Extension;
 class Profile;
 
 // A helper class that takes care of removing local storage, databases and
 // cookies for a given extension. This is used by
 // ExtensionsService::ClearExtensionData() upon uninstalling an extension.
 class ExtensionDataDeleter
   : public base::RefCountedThreadSafe<ExtensionDataDeleter,
                                       ChromeThread::DeleteOnUIThread> {
  public:
   ExtensionDataDeleter(Profile* profile, const GURL& extension_url);
@@ skipping 29 matching lines @@
   // The security origin identifier for which we're deleting stuff.
   string16 origin_id_;
 
   // Webkit context for accessing the DOM storage helper.
   scoped_refptr<WebKitContext> webkit_context_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionDataDeleter);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_DATA_DELETER_H_