Let Chrome app handle Ash accelerators first if the app is launched as a window

ash/accelerators/accelerator_controller.h

Index: ash/accelerators/accelerator_controller.h
diff --git a/ash/accelerators/accelerator_controller.h b/ash/accelerators/accelerator_controller.h
index 45ca052072ad384f9fab93544d1549612d5eaf7f..1c8193d443f7c32995498f1506e2833ca6c035d6 100644
--- a/ash/accelerators/accelerator_controller.h
+++ b/ash/accelerators/accelerator_controller.h
@@ -56,6 +56,9 @@ class ASH_EXPORT AcceleratorController : public ui::AcceleratorTarget {
   // Returns true if an accelerator was activated.
   bool Process(const ui::Accelerator& accelerator);
 
+  // Returns true if the |accelerator| is registered.
+  bool IsRegistered(const ui::Accelerator& accelerator) const;
+
   // Overridden from ui::AcceleratorTarget:
   virtual bool AcceleratorPressed(const ui::Accelerator& accelerator) OVERRIDE;
   virtual bool CanHandleAccelerators() const OVERRIDE;