Refactor kiosk app launch to be part of login screen UI flow.

chrome/browser/chromeos/login/login_display_host.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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_LOGIN_LOGIN_DISPLAY_HOST_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_LOGIN_DISPLAY_HOST_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 80 matching lines @@
   virtual void StartSignInScreen() = 0;
 
   // Resumes a previously started sign in screen.
   virtual void ResumeSignInScreen() = 0;
 
   // Invoked when system preferences that affect the signin screen have changed.
   virtual void OnPreferencesChanged() = 0;
 
   // Initiates authentication network prewarming.
   virtual void PrewarmAuthentication() = 0;
+
+  // Starts app launch splash screen.
+  virtual void StartAppLaunch(const std::string& app_id) = 0;
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_LOGIN_DISPLAY_HOST_H_