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

extensions/shell/browser/shell_browser_main_delegate.h

Index: extensions/shell/browser/shell_browser_main_delegate.h
diff --git a/extensions/shell/browser/shell_browser_main_delegate.h b/extensions/shell/browser/shell_browser_main_delegate.h
index 1b234c514d3c131a6f8a3485d66b6ea5a6cf08f2..a3ddf7f298654fbfe97750a2af411b59e4162d6f 100644
--- a/extensions/shell/browser/shell_browser_main_delegate.h
+++ b/extensions/shell/browser/shell_browser_main_delegate.h
@@ -25,9 +25,9 @@ class ShellBrowserMainDelegate {
   // other services such as BrowserContext / extension system are shut down.
   virtual void Shutdown() = 0;
 
-  // Creates the ShellDesktopController instance to initialize the root window
-  // and window manager. Subclass may return its subclass to customize the
-  // windo manager.
+  // Creates the ShellDesktopControllerAura instance to initialize the root
+  // window and window manager. Subclass may return its subclass to customize
+  // the window manager.
   virtual DesktopController* CreateDesktopController() = 0;
 };