Properly handle user cancellation of signin.

chrome/browser/signin/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.
 //
 // The signin manager encapsulates some functionality tracking
 // which user is signed in. When a user is signed in, a ClientLogin
 // request is run on their behalf. Auth tokens are fetched from Google
 // and the results are stored in the TokenService.
 //
 // **NOTE** on semantics of SigninManager:
@@ skipping 290 matching lines @@
   void TransferCredentialsToNewProfile();
 
   // Helper function that loads policy with the passed CloudPolicyClient, then
   // completes the signin process.
   void LoadPolicyWithCachedClient();
 
   // Callback invoked once a profile is created, so we can complete the
   // credentials transfer and load policy.
   void CompleteSigninForNewProfile(Profile* profile,
                                    Profile::CreateStatus status);
+
+  // Cancels the in-progress signin for this profile.
+  void CancelSignin();
 #endif  // defined(ENABLE_CONFIGURATION_POLICY) && !defined(OS_CHROMEOS)
 
   // Invoked once policy has been loaded to complete user signin.
   void CompleteSigninAfterPolicyLoad();
 
   // ClientLogin identity.
   std::string possibly_invalid_username_;
   std::string password_;  // This is kept empty whenever possible.
   bool had_two_factor_error_;
 
@@ skipping 60 matching lines @@
 #if defined(ENABLE_CONFIGURATION_POLICY) && !defined(OS_CHROMEOS)
   // CloudPolicyClient reference we keep while determining whether to create
   // a new profile for an enterprise user or not.
   scoped_ptr<policy::CloudPolicyClient> policy_client_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(SigninManager);
 };
 
 #endif  // CHROME_BROWSER_SIGNIN_SIGNIN_MANAGER_H_