components: Cleanup class/struct fwd declarations

components/signin/core/browser/fake_gaia_cookie_manager_service.h

 // Copyright 2015 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 COMPONENTS_SIGNIN_CORE_BROWSER_FAKE_GAIA_COOKIE_MANAGER_SERVICE_H_
 #define COMPONENTS_SIGNIN_CORE_BROWSER_FAKE_GAIA_COOKIE_MANAGER_SERVICE_H_
 
 #include <memory>
 #include <string>
 
 #include "base/macros.h"
 #include "components/signin/core/browser/gaia_cookie_manager_service.h"
 #include "net/url_request/test_url_fetcher_factory.h"
 
-namespace content {
-class BrowserContext;
-}
-
 class FakeGaiaCookieManagerService : public GaiaCookieManagerService {
  public:
   FakeGaiaCookieManagerService(OAuth2TokenService* token_service,
                                const std::string& source,
                                SigninClient* client);
 
   void Init(net::FakeURLFetcherFactory* url_fetcher_factory);
 
   void SetListAccountsResponseHttpNotFound();
   void SetListAccountsResponseWebLoginRequired();
@@ skipping 19 matching lines @@
       const GaiaCookieManagerService::GaiaCookieRequest& request,
       const std::string& source_default) override;
 
   // Provide a fake response for calls to /ListAccounts.
   net::FakeURLFetcherFactory* url_fetcher_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(FakeGaiaCookieManagerService);
 };
 
 #endif  // COMPONENTS_SIGNIN_CORE_BROWSER_FAKE_GAIA_COOKIE_MANAGER_SERVICE_H_