Add the ability to load multiple apps into app_shell.

extensions/shell/browser/desktop_controller.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 EXTENSIONS_SHELL_BROWSER_DESKTOP_CONTROLLER_H_
 #define EXTENSIONS_SHELL_BROWSER_DESKTOP_CONTROLLER_H_
 
 namespace aura {
 class Window;
 class WindowTreeHost;
@@ skipping 28 matching lines @@
 
   // Creates a new app window and adds it to the desktop. The desktop maintains
   // ownership of the window. The window must be closed before |extension| is
   // destroyed.
   virtual AppWindow* CreateAppWindow(content::BrowserContext* context,
                                      const Extension* extension) = 0;
 
   // Attaches the window to our window hierarchy.
   virtual void AddAppWindow(aura::Window* window) = 0;
 
+  // Removes the window from the desktop.
+  virtual void RemoveAppWindow(AppWindow* window) = 0;
+
   // Closes and destroys the app windows.
   virtual void CloseAppWindows() = 0;
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_SHELL_BROWSER_DESKTOP_CONTROLLER_H_