components: Cleanup class/struct fwd declarations

components/signin/core/browser/fake_account_fetcher_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_ACCOUNT_FETCHER_SERVICE_H_
 #define COMPONENTS_SIGNIN_CORE_BROWSER_FAKE_ACCOUNT_FETCHER_SERVICE_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "components/signin/core/browser/account_fetcher_service.h"
 
 class KeyedService;
 
-namespace content {
-class BrowserContext;
-}
-
 // AccountTrackerService is a KeyedService that retrieves and caches GAIA
 // information about Google Accounts.  This fake class can be used in tests
 // to prevent AccountTrackerService from sending network requests.
 class FakeAccountFetcherService : public AccountFetcherService {
  public:
   void FakeUserInfoFetchSuccess(const std::string& email,
                                 const std::string& gaia,
                                 const std::string& hosted_domain,
                                 const std::string& full_name,
                                 const std::string& given_name,
@@ skipping 15 matching lines @@
  private:
   void StartFetchingUserInfo(const std::string& account_id) override;
   void StartFetchingChildInfo(const std::string& account_id) override;
   void SendRefreshTokenAnnotationRequest(
       const std::string& account_id) override;
 
   DISALLOW_COPY_AND_ASSIGN(FakeAccountFetcherService);
 };
 
 #endif  // COMPONENTS_SIGNIN_CORE_BROWSER_FAKE_ACCOUNT_FETCHER_SERVICE_H_