Move NativeAppWindow to extensions

apps/ui/apps_client.h

 // 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.
 
 #ifndef APPS_UI_APPS_CLIENT_H_
 #define APPS_UI_APPS_CLIENT_H_
 
 #include <vector>
 
 #include "apps/app_window.h"
 
 namespace content {
 class BrowserContext;
 }
 
 namespace extensions {
 class Extension;
+class NativeAppWindow;
 }
 
 namespace apps {
 
-class NativeAppWindow;
-
 // Sets up global state for the apps system. Should be Set() once in each
 // process. This should be implemented by the client of the apps system.
 class AppsClient {
  public:
   // Get all loaded browser contexts.
   virtual std::vector<content::BrowserContext*> GetLoadedBrowserContexts() = 0;
 
   // Creates a new apps::AppWindow for the app in |extension| for |context|.
   // Caller takes ownership.
   virtual AppWindow* CreateAppWindow(
       content::BrowserContext* context,
       const extensions::Extension* extension) = 0;
 
-  // Creates a new apps::NativeAppWindow for |window|.
-  virtual NativeAppWindow* CreateNativeAppWindow(
+  // Creates a new extensions::NativeAppWindow for |window|.
+  virtual extensions::NativeAppWindow* CreateNativeAppWindow(
       AppWindow* window,
       const AppWindow::CreateParams& params) = 0;
 
   // A positive keep-alive count is a request for the embedding application to
   // keep running after all windows are closed. The count starts at zero.
   virtual void IncrementKeepAliveCount() = 0;
   virtual void DecrementKeepAliveCount() = 0;
 
   // Return the apps client.
   static AppsClient* Get();
 
   // Initialize the apps system with this apps client.
   static void Set(AppsClient* client);
 };
 
 }  // namespace apps
 
 #endif  // APPS_UI_APPS_CLIENT_H_