[ash-md] Fixed MenuButton focus appearing after dismissing menus.

ui/views/controls/button/menu_button.cc

Index: ui/views/controls/button/menu_button.cc
diff --git a/ui/views/controls/button/menu_button.cc b/ui/views/controls/button/menu_button.cc
index af3cd2c3f7d70f71dffd333af148474317cfd354..e6707f3d289a39ab01a71bc36c4bb65d5091d5cd 100644
--- a/ui/views/controls/button/menu_button.cc
+++ b/ui/views/controls/button/menu_button.cc
@@ -401,6 +401,12 @@ void MenuButton::DecrementPressedLocked() {
     // try to add an ink drop effect.
     if (GetWidget() && state() != STATE_PRESSED)
       AnimateInkDrop(InkDropState::DEACTIVATED, nullptr /* event */);
+
+    // The Widget can be null in tests.
+    if (GetWidget()) {

[sky, 2017/05/14 15:52:25]

What about dispatching the event at the time the menu is shown? Doing it later
seems rather after the fact and potentially problematic.

+      // Force MOUSE_ENTER/EXIT events so button hover states are updated.
+      GetWidget()->SynthesizeMouseMoveEvent(true);
+    }
   }
 }