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

ash/accelerators/accelerator_controller.cc

Index: ash/accelerators/accelerator_controller.cc
diff --git a/ash/accelerators/accelerator_controller.cc b/ash/accelerators/accelerator_controller.cc
index 9f287b5e4228ef9e20b7727a7a9fbe9593e2e36d..4d0e5280c73249ca0ed40a82eb90962e7f2229d5 100644
--- a/ash/accelerators/accelerator_controller.cc
+++ b/ash/accelerators/accelerator_controller.cc
@@ -281,6 +281,10 @@ bool AcceleratorController::Process(const ui::Accelerator& accelerator) {
   return accelerator_manager_->Process(accelerator);
 }
 
+bool AcceleratorController::IsAccelerator(const ui::Accelerator& accelerator) {
+  return accelerator_manager_->GetCurrentTarget(accelerator) != NULL;
+}
+
 void AcceleratorController::SetBrightnessControlDelegate(
     scoped_ptr<BrightnessControlDelegate> brightness_control_delegate) {
   brightness_control_delegate_.swap(brightness_control_delegate);