Only dispatch menu events if they have a valid target.

ui/events/event_utils.cc

Index: ui/events/event_utils.cc
diff --git a/ui/events/event_utils.cc b/ui/events/event_utils.cc
index e5a319e10f15bf0daab6633f98588eb86fd0b272..ad7820fdebc5997d4e9a680f26a6bab5df1371c0 100644
--- a/ui/events/event_utils.cc
+++ b/ui/events/event_utils.cc
@@ -16,6 +16,44 @@ namespace {
 int g_custom_event_types = ET_LAST;
 }  // namespace
 
+Event* EventFromNative(const base::NativeEvent& native_event) {
+  EventType type = EventTypeFromNative(native_event);
+  switch(type) {
+    case ET_KEY_PRESSED:
+    case ET_KEY_RELEASED:
+      return new KeyEvent(native_event, false);
+
+    case ET_TRANSLATED_KEY_PRESS:
+    case ET_TRANSLATED_KEY_RELEASE:
+      return new TranslatedKeyEvent(native_event, false);
+
+    case ET_MOUSE_PRESSED:
+    case ET_MOUSE_DRAGGED:
+    case ET_MOUSE_RELEASED:
+    case ET_MOUSE_MOVED:
+    case ET_MOUSE_ENTERED:
+    case ET_MOUSE_EXITED:
+      return new MouseEvent(native_event);
+
+    case ET_MOUSEWHEEL:
+      return new MouseWheelEvent(native_event);
+
+    case ET_SCROLL_FLING_START:
+    case ET_SCROLL_FLING_CANCEL:
+    case ET_SCROLL:
+      return new ScrollEvent(native_event);
+
+    case ET_TOUCH_RELEASED:
+    case ET_TOUCH_PRESSED:
+    case ET_TOUCH_MOVED:
+    case ET_TOUCH_CANCELLED:
+      return new TouchEvent(native_event);
+
+    default:
+      return NULL;
+  }
+}
+
 int RegisterCustomEventType() {
   return ++g_custom_event_types;
 }