Exiting menu mode when content preview is clicked

chrome/browser/resources/vr_shell/vr_shell_ui.css

 /* Copyright 2016 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. */
 
 html {
   background-color: rgba(255, 255, 255, 0);
 }
 
 #ui {
   left: 0;
@@ skipping 127 matching lines @@
 #reload-ui-button {
   color: white;
   font-size: 24px;
   padding: 12px;
 }
 
 #reload-ui-button:hover {
   background-color: pink;
 }
 
+#content-interceptor {
+  height: 1px;
+  opacity: 0;
+  width: 1px;
+}
+
 .tab {
   background-color: #eee;
   border-radius: 6px;
   color: black;
   display: inline-block;
   font-size: 20px;
   height: 30px;
   line-height: 30px;
   margin: 0 15px 0 15px;
   overflow: hidden;
@@ skipping 147 matching lines @@
   outline: none; /* Do not show an outline when focused. */
   overflow: hidden;
   white-space: nowrap;
   width: 100%;
 }
 
 #omnibox-clear-button {
   background: url(../../../../ui/webui/resources/images/x-hover.png) no-repeat center center;
   width: 18px;
 }