arc: Make Play Store item persistance in shelf.

chrome/browser/ui/app_list/arc/arc_app_utils.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_UTILS_H_
 #define CHROME_BROWSER_UI_APP_LIST_ARC_ARC_APP_UTILS_H_
 
 #include <string>
 
 #include "base/callback.h"
 #include "ui/gfx/geometry/rect.h"
 
 namespace content {
 class BrowserContext;
 }
 
 namespace arc {
 
+extern const char kPlayStoreAppId[];

[oshima, 2016/05/13 16:53:27]

do you need extern? This is necessary only if this is linked into shared
library.

[oshima, 2016/05/13 16:54:38]

Ahh, never mind. I was somehow confused with export. I think I need more sleep. 

+
 using CanHandleResolutionCallback = base::Callback<void(bool)>;
 
 // Launch an app and let the system decides how big and where to place it.
 bool LaunchApp(content::BrowserContext* context, const std::string& app_id);
 
 // Launch an app with given layout and let the system decides how big and where
 // to place it.
 bool LaunchApp(content::BrowserContext* context,
                const std::string& app_id,
                bool landscape_layout);
@@ skipping 11 matching lines @@
     const std::string& app_id,
     const gfx::Rect& rect,
     const CanHandleResolutionCallback& callback);
 
 // Uninstalls the package in ARC.
 void UninstallPackage(const std::string& package_name);
 
 }  // namespace arc
 
 #endif  // CHROME_BROWSER_UI_APP_LIST_ARC_ARC_APP_UTILS_H_