Cleanup: Remove some unneeded Extension* class forward declarations.

chrome/browser/extensions/api/permissions/permissions_api.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 CHROME_BROWSER_EXTENSIONS_API_PERMISSIONS_PERMISSIONS_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_PERMISSIONS_PERMISSIONS_API_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "chrome/browser/extensions/chrome_extension_function.h"
 #include "chrome/browser/extensions/extension_install_prompt.h"
 #include "extensions/common/permissions/permission_set.h"
 
-class ExtensionService;
-
 namespace extensions {
 
 // chrome.permissions.contains
 class PermissionsContainsFunction : public ChromeSyncExtensionFunction {
  public:
   DECLARE_EXTENSION_FUNCTION("permissions.contains", PERMISSIONS_CONTAINS)
 
  protected:
   virtual ~PermissionsContainsFunction() {}
 
@@ skipping 48 matching lines @@
   virtual bool RunAsync() OVERRIDE;
 
  private:
   scoped_ptr<ExtensionInstallPrompt> install_ui_;
   scoped_refptr<extensions::PermissionSet> requested_permissions_;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_PERMISSIONS_PERMISSIONS_API_H_