Make pop-up menus more easily dismissable.

remoting/webapp/window_frame.css

 /* Copyright 2014 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.
  */
 
 .window-body {
   position: relative;
 }
 
 html.apps-v2,
@@ skipping 18 matching lines @@
 
 .window-title {
   line-height: 32px;
   font-size: 14px;
 }
 
 .title-bar .window-title {
   padding-__MSG_@@bidi_start_edge__: 12px;
   width: 100%;
   display: inline-block;
+  flex: 1;
+}
+
+.title-bar:not(.menu-opened) .window-title {
   -webkit-app-region: drag;
-  flex: 1;
 }
 
 .window-control {
   width: 32px;
   height: 32px;
   padding-top: 9px;
   padding-right: 1px;
   text-align: center;
   display: inline-block;
 }
@@ skipping 138 matching lines @@
   box-shadow: 1px 1px 10px rgba(0, 0, 0, 0.5);
 }
 
 .fullscreen .title-bar.opened .window-controls-stub {
   background-color: #a6a6a6;
 }
 
 body.fullscreen .window-fullscreen {
   display: none;
 }