Part 1 of work to do user sign in based on OAuth2:

chrome/common/net/gaia/gaia_auth_consumer.h

 // Copyright (c) 2011 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_COMMON_NET_GAIA_GAIA_AUTH_CONSUMER_H_
 #define CHROME_COMMON_NET_GAIA_GAIA_AUTH_CONSUMER_H_
 #pragma once
 
 #include <string>
 
@@ skipping 24 matching lines @@
   virtual ~GaiaAuthConsumer() {}
 
   virtual void OnClientLoginSuccess(const ClientLoginResult& result) {}
   virtual void OnClientLoginFailure(const GoogleServiceAuthError& error) {}
 
   virtual void OnIssueAuthTokenSuccess(const std::string& service,
                                        const std::string& auth_token) {}
   virtual void OnIssueAuthTokenFailure(const std::string& service,
                                        const GoogleServiceAuthError& error) {}
 
+  virtual void OnOAuthLoginTokenSuccess(const std::string& refresh_token,
+                                        const std::string& access_token,
+                                        int expires_in_secs) {}
+  virtual void OnOAuthLoginTokenFailure(const GoogleServiceAuthError& error) {}
+
   virtual void OnGetUserInfoSuccess(const std::string& key,
                                     const std::string& value) {}
   virtual void OnGetUserInfoKeyNotFound(const std::string& key) {}
   virtual void OnGetUserInfoFailure(const GoogleServiceAuthError& error) {}
 
   virtual void OnTokenAuthSuccess(const std::string& data) {}
   virtual void OnTokenAuthFailure(const GoogleServiceAuthError& error) {}
 
   virtual void OnMergeSessionSuccess(const std::string& data) {}
   virtual void OnMergeSessionFailure(const GoogleServiceAuthError& error) {}
 };
 
 #endif  // CHROME_COMMON_NET_GAIA_GAIA_AUTH_CONSUMER_H_