Ensure that menus put in Chrome ASH on Windows 8 are operatable using the keyboard.

ui/aura/remote_root_window_host_win.h

Index: ui/aura/remote_root_window_host_win.h
===================================================================
--- ui/aura/remote_root_window_host_win.h	(revision 186512)
+++ ui/aura/remote_root_window_host_win.h	(working copy)
@@ -166,6 +166,18 @@
   virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE;
   virtual void PrepareForShutdown() OVERRIDE;
 
+  // Helper function to dispatch a keyboard message to the desired target.
+  // The default target is the RootWindowHostDelegate. For nested message loop
+  // invocations we post a synthetic keyboard message directly into the message
+  // loop. The dispatcher for the nested loop would then decide how this
+  // message is routed.
+  void DispatchKeyboardMessage(ui::EventType type,
+                               uint32 vkey,
+                               uint32 repeat_count,
+                               uint32 scan_code,
+                               uint32 flags,
+                               bool is_character);
+
   RootWindowHostDelegate* delegate_;
   IPC::Sender* host_;
   scoped_ptr<ui::ViewProp> prop_;