mash: Don't close system tray bubble for clicks in menus/notifications

ui/views/mus/native_widget_mus.cc

Index: ui/views/mus/native_widget_mus.cc
diff --git a/ui/views/mus/native_widget_mus.cc b/ui/views/mus/native_widget_mus.cc
index 3f2e687781d3d6b8b84772df1b3a4def20fc69e8..db4a21aaf7cd0b210bfd001fda2e6cf261bca2fb 100644
--- a/ui/views/mus/native_widget_mus.cc
+++ b/ui/views/mus/native_widget_mus.cc
@@ -377,6 +377,17 @@ void NativeWidgetMus::NotifyFrameChanged(
   }
 }
 
+// static
+Widget* NativeWidgetMus::GetWidgetForWindow(mus::Window* window) {
+  if (!window)
+    return nullptr;
+  NativeWidgetMus* native_widget =
+      window->GetLocalProperty(kNativeWidgetMusKey);
+  if (!native_widget)
+    return nullptr;
+  return native_widget->GetWidget();
+}
+
 aura::Window* NativeWidgetMus::GetRootWindow() {
   return window_tree_host_->window();
 }