Add deprecation warning banner to App Launcher on Mac.

chrome/app/google_chrome_strings.grd

 <?xml version="1.0" encoding="UTF-8"?>
 <!-- This file contains definitions of strings that are specific to
 Google Chrome. These strings will be translated for each locale that Google
 Chrome supports. If you update this file, be sure also to update
 chromium_strings.grd. -->
 
 <grit base_dir="." latest_public_release="0" current_release="1"
       source_lang_id="en" enc_check="möl">
   <outputs>
     <output filename="grit/google_chrome_strings.h" type="rc_header">
@@ skipping 861 matching lines @@
         <if expr="not use_titlecase">
           <message name="IDS_APP_LIST_EXTENSIONS_UNINSTALL" desc="Title text for the context menu item of a non-platform-app app list item that removes the app.">
             Remove from Chrome...
           </message>
         </if>
         <if expr="use_titlecase">
           <message name="IDS_APP_LIST_EXTENSIONS_UNINSTALL" desc="In Title Case: Title text for the context menu item of a non-platform-app app list item that removes the app.">
             Remove From Chrome...
           </message>
         </if>
+        <if expr="not chromeos">
+          <message name="IDS_APP_LIST_MESSAGE_TITLE" desc="Title given to the message displayed in the app launcher to say it is going away">
+            The Chrome App Launcher is going away.
+          </message>
+          <message name="IDS_APP_LIST_MESSAGE_TEXT" desc="The message body text displayed in the app launcher to say it is going away">
+            Use the <ph name="APPS_ICON_IMAGE">$1<ex>Apps</ex></ph> shortcut in the Chrome bookmarks bar to continue accessing your apps.
+          </message>
+        </if>
       </if>
 
       <!-- App shortcuts -->
       <message name="IDS_APP_SHORTCUTS_SUBDIR_NAME" desc="Name for the Chrome Apps Start Menu folder name.">
         Chrome Apps
       </message>
       <message name="IDS_APP_SHORTCUTS_SUBDIR_NAME_CANARY" desc="Name for the Chrome Apps Start Menu folder name for the Canary channel.">
         Chrome Canary Apps
       </message>
 
@@ skipping 275 matching lines @@
         </message>
         <message name="IDS_METRO_FLOW_LOGO_STRING_ALT"
                  desc="Alt text for the faded Chrome logo image.">
           Chrome logo
         </message>
       </if>
 
     </messages>
   </release>
 </grit>