cros: Make sure views-based lock screen is destroyed after it is dismissed.

chrome/browser/chromeos/login/lock/webui_screen_locker.cc

 // Copyright 2014 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/chromeos/login/lock/webui_screen_locker.h"
 
 #include "base/command_line.h"
 #include "base/feature_list.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 299 matching lines @@
 }
 
 bool WebUIScreenLocker::IsSigninInProgress() const {
   // The way how screen locker is implemented right now there's no
   // GAIA sign in in progress in any case.
   return false;
 }
 
 void WebUIScreenLocker::Login(const UserContext& user_context,
                               const SigninSpecifics& specifics) {
-  chromeos::ScreenLocker::default_screen_locker()->Authenticate(user_context);
+  chromeos::ScreenLocker::default_screen_locker()->Authenticate(
+      user_context, base::BindOnce([](bool auth_success) {}));

[xiyuan, 2017/06/06 22:37:52]

nit: Use ScreenLocker::AuthenticateCallback() to create a null callback since we
don't care.

[jdufault, 2017/06/07 18:58:35]

Done.

 }
 
 void WebUIScreenLocker::MigrateUserData(const std::string& old_password) {
   NOTREACHED();
 }
 
 void WebUIScreenLocker::OnSigninScreenReady() {
   VLOG(2) << "Lock screen signin screen is ready";
 }
 
@@ skipping 105 matching lines @@
   }
 
   if (GetOobeUI()) {
     const gfx::Size& size = primary_display.size();
     GetOobeUI()->GetCoreOobeView()->SetClientAreaSize(size.width(),
                                                       size.height());
   }
 }
 
 }  // namespace chromeos