Resolve new GAIA flow's infinite loop.

chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.cc

 // Copyright 2013 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/ui/webui/chromeos/login/gaia_screen_handler.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/prefs/pref_service.h"
@@ skipping 606 matching lines @@
 }
 
 void GaiaScreenHandler::StartClearingCookies(
     const base::Closure& on_clear_callback) {
   cookies_cleared_ = false;
   ProfileHelper* profile_helper = ProfileHelper::Get();
   LOG_ASSERT(Profile::FromWebUI(web_ui()) ==
              profile_helper->GetSigninProfile());
   profile_helper->ClearSigninProfile(
       base::Bind(&GaiaScreenHandler::OnCookiesCleared,
-                 weak_factory_.GetWeakPtr(),
-                 on_clear_callback));
+                 weak_factory_.GetWeakPtr(), on_clear_callback),
+      StartupUtils::IsWebviewSigninEnabled() ? web_ui()->GetWebContents()
+                                             : nullptr);
 }
 
 void GaiaScreenHandler::OnCookiesCleared(
     const base::Closure& on_clear_callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   cookies_cleared_ = true;
   on_clear_callback.Run();
 }
 
 void GaiaScreenHandler::ShowSigninScreenForCreds(const std::string& username,
@@ skipping 182 matching lines @@
 SigninScreenHandlerDelegate* GaiaScreenHandler::Delegate() {
   DCHECK(signin_screen_handler_);
   return signin_screen_handler_->delegate_;
 }
 
 void GaiaScreenHandler::SetSigninScreenHandler(SigninScreenHandler* handler) {
   signin_screen_handler_ = handler;
 }
 
 }  // namespace chromeos