arc: Make Play Store item persistent in app list.

chrome/browser/ui/app_list/arc/arc_app_launcher.h

 // Copyright 2016 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_UI_APP_LIST_ARC_ARC_APP_LAUNCHER_H_
 #define CHROME_BROWSER_UI_APP_LIST_ARC_ARC_APP_LAUNCHER_H_
 
 #include <string>
 
 #include "base/macros.h"
@@ skipping 10 matching lines @@
   ArcAppLauncher(content::BrowserContext* context,
                  const std::string& app_id,
                  bool landscape_layout);
   ~ArcAppLauncher() override;
 
   bool app_launched() const { return app_launched_; }
 
   // ArcAppListPrefs::Observer:
   void OnAppRegistered(const std::string& app_id,
                        const ArcAppListPrefs::AppInfo& app_info) override;
+  void OnAppReadyChanged(const std::string& app_id, bool ready) override;
 
  private:
   void LaunchApp();
 
   // Unowned pointer.
   content::BrowserContext* context_;
   // Arc app id and requested layout.
   const std::string app_id_;
   const bool landscape_layout_;
   // Flag idicating that Arc app was launched.
   bool app_launched_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(ArcAppLauncher);
 };
 
 #endif  // CHROME_BROWSER_UI_APP_LIST_ARC_ARC_APP_LAUNCHER_H_