Add a Record button to the web-app if the host supports video recording.

remoting/webapp/html/window_frame.html

 <!--
 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.
 -->
 <div id="title-bar" class="title-bar apps-v2-only">
   <span class="window-title">&nbsp;</span>
   <span class="window-controls-hover-target">
     <div class="window-controls">
       <span i18n-title="OPTIONS_MENU"
             class="window-control window-options menu-button">
         <span class="menu-button-activator">
           <img src="icon_options.webp">
         </span>
         <ul class="window-options-menu right-align">
+          <li class="menu-start-stop-recording"
+              i18n-content="START_STOP_RECORDING" hidden></li>
           <li class="menu-send-ctrl-alt-del"
               i18n-content="SEND_CTRL_ALT_DEL"></li>
           <li class="menu-send-print-screen"
               i18n-content="SEND_PRINT_SCREEN"></li>
           <li class="menu-separator"></li>
           <li class="menu-resize-to-client"
               i18n-content="RESIZE_TO_CLIENT"></li>
           <li class="menu-shrink-to-fit"
               i18n-content="SHRINK_TO_FIT"></li>
           <li class="menu-separator"></li>
@@ skipping 19 matching lines @@
         <img src="icon_maximize_restore.webp">
       </span>
       <span i18n-title="CLOSE_WINDOW"
             class="window-control window-close">
         <img src="icon_close.webp">
       </span>
     </div>
     <div class="window-controls-stub">&nbsp;</div>
   </span>
 </div>