add ash_resources.grd and necessary changes to use images in ash/resources

ash/display/display_controller.h

Index: ash/display/display_controller.h
diff --git a/ash/display/display_controller.h b/ash/display/display_controller.h
index 218ab21c99bf3fba1e8264e10991ac14a522d561..5e338bef9fb133afad5f9e8a20563d724ce31d91 100644
--- a/ash/display/display_controller.h
+++ b/ash/display/display_controller.h
@@ -114,6 +114,10 @@ class ASH_EXPORT DisplayController : public aura::DisplayObserver {
                                const DisplayLayout& layout);
   const DisplayLayout& GetLayoutForDisplayName(const std::string& name);
 
+  // Swaps primary and secondary display. This also updated DisplayLayout so that
+  // the phisical display layout does not change.
+  void SwapPrimaryAndSecondary();
+
   // aura::DisplayObserver overrides:
   virtual void OnDisplayBoundsChanged(
       const gfx::Display& display) OVERRIDE;