Mac: Add "Show Tab Overview" menu item.

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. -->
 
 <grit base_dir="." latest_public_release="0" current_release="1"
       source_lang_id="en" enc_check="möl">
   <outputs>
     <output filename="grit/generated_resources.h" type="rc_header">
       <emit emit_type='prepend'></emit>
@@ skipping 7456 matching lines @@
                  desc="The Mac menu item for zoom (maximize) in the window menu."
                  meaning="Mac Menubar: The Mac menu item for zoom (maximize) in the window menu.">
           Zoom
         </message>
         <message name="IDS_NEXT_TAB_MAC" desc="The Mac menu item for next tab in the window menu.">
           Select Next Tab
         </message>
         <message name="IDS_PREV_TAB_MAC" desc="The Mac menu item for previous tab in the window menu.">
           Select Previous Tab
         </message>
+        <message name="IDS_SHOW_TABPOSE_MAC" desc="The Mac menu item for showing a tab overview. This item is in the window menu.">
+          Show Tab Overview...
+        </message>
         <message name="IDS_SHOW_DOWNLOADS_MAC" desc="The Mac menu item to show downloads in the window menu.">
           Downloads
         </message>
         <message name="IDS_SHOW_EXTENSIONS_MAC" desc="The Mac menu item to show extensions in the window menu.">
           Extensions
         </message>
         <message name="IDS_ALL_WINDOWS_FRONT_MAC" desc="The Mac menu item for bring all to front the window menu.">
           Bring All to Front
         </message>
         <!-- Help menu -->
@@ skipping 1400 matching lines @@
 
     </messages>
 
     <structures fallback_to_english="true">
       <structure name="IDD_CHROME_FRAME_FIND_DIALOG" file="cf_resources.rc" type="dialog" >
       </structure>
     </structures>
 
   </release>
 </grit>