Refactor ShellDesktopController and ShellNativeAppWindow to allow for non-aura implementations.

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_
 
+#include "ui/gfx/native_widget_types.h"
+
 namespace aura {
 class Window;
 class WindowTreeHost;
 }
 
 namespace content {
 class BrowserContext;
 }
 
+namespace gfx {
+class Size;
+}
+
 namespace extensions {
 class AppWindow;
 class Extension;
 class ShellAppWindow;
 
 // DesktopController is an interface to construct the window environment in
-// extensions shell. ShellDesktopController provides a default implementation
-// for app_shell, and embedder (such as athena) can provide its own.
+// extensions shell. ShellDesktopControllerAura provides a default
+// implementation for app_shell, and other embedders (such as athena) can
+// provide their own.
 // TODO(jamescook|oshima): Clean up this interface now that there is only one
 // way to create an app window.
 class DesktopController {
  public:
   DesktopController();
   virtual ~DesktopController();
 
   // Returns the single instance of the desktop. (Stateless functions like
   // ShellAppWindowCreateFunction need to be able to access the desktop, so
   // we need a singleton somewhere).
   static DesktopController* instance();
 
-  // Returns the WindowTreeHost created by this DesktopController.
-  virtual aura::WindowTreeHost* GetHost() = 0;
+  // Get the size of the window created by this DesktopController. This should
+  // typically be full-screen.
+  virtual gfx::Size GetWindowSize() = 0;
 
   // 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;
+  virtual void AddAppWindow(gfx::NativeWindow 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_