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

extensions/shell/browser/desktop_controller.h

Index: extensions/shell/browser/desktop_controller.h
diff --git a/extensions/shell/browser/desktop_controller.h b/extensions/shell/browser/desktop_controller.h
index 40a4e537e8ab2f0395953d6de56a7be27ff89719..84e02fea1a0f13af6363ca79b7d8de00d9eaa6d4 100644
--- a/extensions/shell/browser/desktop_controller.h
+++ b/extensions/shell/browser/desktop_controller.h
@@ -5,6 +5,8 @@
 #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;
@@ -14,14 +16,19 @@ 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 {
@@ -34,8 +41,9 @@ class DesktopController {
   // 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
@@ -44,7 +52,7 @@ class DesktopController {
                                      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;