chrome: Cleanup class/struct forward declarations

chrome/browser/signin/chrome_signin_client.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.
 
 #ifndef CHROME_BROWSER_SIGNIN_CHROME_SIGNIN_CLIENT_H_
 #define CHROME_BROWSER_SIGNIN_CHROME_SIGNIN_CLIENT_H_
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "build/build_config.h"
 #include "components/signin/core/browser/signin_client.h"
 #include "components/signin/core/browser/signin_error_controller.h"
 #include "google_apis/gaia/gaia_oauth_client.h"
 #include "google_apis/gaia/oauth2_token_service.h"
 
 #if !defined(OS_CHROMEOS)
 #include "net/base/network_change_notifier.h"
 #endif
 
-namespace content_settings {
-class CookieSettings;
-}
-
 namespace net {
 class URLRequestContext;
 }
 
 class Profile;
 
 class ChromeSigninClient
     : public SigninClient,
 #if !defined(OS_CHROMEOS)
       public net::NetworkChangeNotifier::NetworkChangeObserver,
@@ skipping 99 matching lines @@
   std::unique_ptr<OAuth2TokenService::Request> oauth_request_;
 
   // These members are used to debug channel id binding problems in chrome.
   void* request_context_pointer_;
   int number_of_request_context_pointer_changes_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeSigninClient);
 };
 
 #endif  // CHROME_BROWSER_SIGNIN_CHROME_SIGNIN_CLIENT_H_