Signin/OAuth: Create an AccessTokenFetcher helper class

components/signin/core/browser/fake_signin_manager.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 COMPONENTS_SIGNIN_CORE_BROWSER_FAKE_SIGNIN_MANAGER_H_
 #define COMPONENTS_SIGNIN_CORE_BROWSER_FAKE_SIGNIN_MANAGER_H_
 
 #include <memory>
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "build/build_config.h"
 #include "components/signin/core/browser/signin_manager.h"
 #include "components/signin/core/browser/signin_metrics.h"
 
 // SigninManager to use for testing. Tests should use the type
 // SigninManagerForTesting to ensure that the right type for their platform is
 // used.
 
-// Overrides InitTokenService to do-nothing in tests.
 class FakeSigninManagerBase : public SigninManagerBase {
  public:
   FakeSigninManagerBase(SigninClient* client,
                         AccountTrackerService* account_tracker_service);
   ~FakeSigninManagerBase() override;
 
   void SignIn(const std::string& account_id);
 };
 
 #if !defined(OS_CHROMEOS)
@@ skipping 34 matching lines @@
 
   void CompletePendingSignin() override;
 
   // Username specified in StartSignInWithRefreshToken() call.
   std::string username_;
 };
 
 #endif  // !defined (OS_CHROMEOS)
 
 #endif  // COMPONENTS_SIGNIN_CORE_BROWSER_FAKE_SIGNIN_MANAGER_H_