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

ui/views/controls/button/menu_button.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/controls/button/menu_button.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "ui/accessibility/ax_node_data.h"
 #include "ui/base/dragdrop/drag_drop_types.h"
 #include "ui/base/resource/resource_bundle.h"
@@ skipping 383 matching lines @@
       desired_state = STATE_DISABLED;
       should_disable_after_press_ = false;
     } else if (ShouldEnterHoveredState()) {
       desired_state = STATE_HOVERED;
     }
     SetState(desired_state);
     // The widget may be null during shutdown. If so, it doesn't make sense to
     // 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);
+    }
   }
 }
 
 int MenuButton::GetMaximumScreenXCoordinate() {
   if (!GetWidget()) {
     NOTREACHED();
     return 0;
   }
 
   gfx::Rect monitor_bounds = GetWidget()->GetWorkAreaBoundsInScreen();
   return monitor_bounds.right() - 1;
 }
 
 }  // namespace views