Add a mode to OAuth2MintTokenFlow that fetches the messages to show to the user.

chrome/browser/extensions/api/identity/identity_api.cc

 // 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.
 
 #include "chrome/browser/extensions/api/identity/identity_api.h"
 
 #include "base/values.h"
 #include "chrome/browser/extensions/extension_function_dispatcher.h"
 #include "chrome/browser/signin/token_service.h"
 #include "chrome/browser/signin/token_service_factory.h"
@@ skipping 25 matching lines @@
 
   if (oauth2_info.scopes.size() == 0) {
     error_ = kInvalidScopes;
     return false;
   }
 
   AddRef();  // Balanced in OnMintTokenSuccess|Failure.
 
   TokenService* token_service = TokenServiceFactory::GetForProfile(profile());
 
-  flow_.reset(
-      new OAuth2MintTokenFlow(profile()->GetRequestContext(), this));
-  flow_->Start(token_service->GetOAuth2LoginRefreshToken(),
-               extension->id(), oauth2_info.client_id, oauth2_info.scopes);
+  flow_.reset(new OAuth2MintTokenFlow(
+      profile()->GetRequestContext(),
+      this,
+      OAuth2MintTokenFlow::Parameters(
+          token_service->GetOAuth2LoginRefreshToken(),
+          extension->id(),
+          oauth2_info.client_id,
+          oauth2_info.scopes,
+          OAuth2MintTokenFlow::MODE_MINT_TOKEN_FORCE)));
+  flow_->Start();
 
   return true;
 }
 
 void GetAuthTokenFunction::OnMintTokenSuccess(const std::string& access_token) {
   result_.reset(Value::CreateStringValue(access_token));
   SendResponse(true);
   Release();  // Balanced in RunImpl.
 }
 
 void GetAuthTokenFunction::OnMintTokenFailure(
     const GoogleServiceAuthError& error) {
   error_ = error.ToString();
   SendResponse(false);
   Release();  // Balanced in RunImpl.
 }
 
 }  // namespace extensions