The key event should be stopped propagation when it's been processed as an accelerator.

ui/views/widget/native_widget_aura.cc

Index: ui/views/widget/native_widget_aura.cc
diff --git a/ui/views/widget/native_widget_aura.cc b/ui/views/widget/native_widget_aura.cc
index 12b6255aef37b20057298db70b940b3f7b58f890..dee6677b3a0d2600d45b08a9bdc108147e0219fc 100644
--- a/ui/views/widget/native_widget_aura.cc
+++ b/ui/views/widget/native_widget_aura.cc
@@ -875,8 +875,10 @@ void NativeWidgetAura::OnKeyEvent(ui::KeyEvent* event) {
 
   FocusManager* focus_manager = GetWidget()->GetFocusManager();
   delegate_->OnKeyEvent(event);
-  if (!event->handled() && focus_manager)
-    focus_manager->OnKeyEvent(*event);
+  if (!event->handled() && focus_manager) {
+    if (!focus_manager->OnKeyEvent(*event))
+      event->StopPropagation();
+  }

[sadrul, 2016/02/17 21:17:55]

Should this code just move into Widget::OnKeyEvent()? That way, we don't need to
duplicate this code in NWA and DNWA (and also in NativeWidgetMus)

[Shu Chen, 2016/02/18 00:29:54]

Done. Good idea.

   event->SetHandled();
 }