Adds button to VRShell menu mode, which lets the user manually exit WebVR presentation.

chrome/app/generated_resources.grd

 <?xml version="1.0" encoding="utf-8"?>
 
 <!--
 This file contains definitions of resources that will be translated for each
 locale.  The variables is_win, is_macosx, is_linux, and is_posix are available
 for making strings OS specific.  Other platform defines such as use_titlecase
 are declared in build/common.gypi.
 -->
 
 <grit base_dir="." latest_public_release="0" current_release="1"
@@ skipping 12246 matching lines @@
     <if expr="is_android">
       <message name="IDS_VR_SHELL_UI_BACK_BUTTON" desc="Text under the VR scene history back button">
         Back
       </message>
       <message name="IDS_VR_SHELL_UI_FORWARD_BUTTON" desc="Text under the VR scene history forward button">
         Forward
       </message>
       <message name="IDS_VR_SHELL_UI_RELOAD_BUTTON" desc="Text under the VR scene reload page button">
         Reload
       </message>
+      <message name="IDS_VR_SHELL_UI_EXIT_PRESENT_BUTTON" desc="Text under the VR scene exit present button">
+        Exit Presentation
+      </message>
       <message name="IDS_VR_SHELL_NEW_TAB_BUTTON" desc="Text on the VR scene new tab button">
         New Tab
       </message>
       <message name="IDS_VR_SHELL_NEW_INCOGNITO_TAB_BUTTON" desc="Text on the VR scene new incognito tab button">
         New Incognito Tab
       </message>
     </if>
 
     <!-- Payment Request -->
     <message name="IDS_PAYMENT_REQUEST_PAYMENT_SHEET_TITLE" desc=" The title on top of the desktop Payment Request Payment Sheet screen">
@@ skipping 126 matching lines @@
       Your downloads appear here
     </message>
 
     <!-- Automation info bar -->
     <message name="IDS_CONTROLLED_BY_AUTOMATION" desc="Message shown when the browser session is being controlled by an automated test.">
       Chrome is being controlled by automated test software.
     </message>
   </messages>
  </release>
 </grit>