Mac: ExternalPopupMenu::close should hide a showing popup menu.

content/browser/renderer_host/webmenurunner_mac.mm

 // Copyright 2013 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 "content/browser/renderer_host/webmenurunner_mac.h"
 
 #include "base/strings/sys_string_conversions.h"
 
 @interface WebMenuRunner (PrivateAPI)
 
@@ skipping 130 matching lines @@
   // Display the menu, and set a flag if a menu item was chosen.
   [cell attachPopUpWithFrame:[dummyView bounds] inView:dummyView];
   [cell performClickWithFrame:[dummyView bounds] inView:dummyView];
 
   [dummyView removeFromSuperview];
 
   if ([self menuItemWasChosen])
     index_ = [cell indexOfSelectedItem];
 }
 
+- (void)hide {
+  [menu_ cancelTracking];
+}
+
 - (int)indexOfSelectedItem {
   return index_;
 }
 
 @end  // WebMenuRunner