MD Settings: About page, updating buttons based on current update status.

chrome/app/settings_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Settings-specific strings (included from generated_resources.grd). -->
 <grit-part>
   <!-- About Page -->
   <if expr="chromeos">
-   <message name="IDS_SETTINGS_ABOUT_PAGE_CURRENT_CHANNEL_STABLE" desc="The stable label in the message about current channel.">
+    <message name="IDS_SETTINGS_ABOUT_PAGE_CHECK_FOR_UPDATES" desc="The button label to check for updates and apply (download and install) if found">
+      Check for updates
+    </message>
+    <message name="IDS_SETTINGS_ABOUT_PAGE_CURRENT_CHANNEL_STABLE" desc="The stable label in the message about current channel.">
       stable
     </message>
     <message name="IDS_SETTINGS_ABOUT_PAGE_CURRENT_CHANNEL_BETA" desc="The beta label in the message about current channel.">
       beta
     </message>
     <message name="IDS_SETTINGS_ABOUT_PAGE_CURRENT_CHANNEL_DEV" desc="The dev label in the message about current channel.">
       dev
     </message>
     <message name="IDS_SETTINGS_ABOUT_PAGE_CURRENT_CHANNEL" desc="The message about current channel.">
       Currently on <ph name="CHANNEL_NAME">$1<ex>stable</ex></ph>
     </message>
+    <message name="IDS_SETTINGS_ABOUT_PAGE_RELAUNCH" desc="The label for the relaunch button that relaunches the browser once update is complete">
+      Restart
+    </message>
+    <message name="IDS_SETTINGS_ABOUT_PAGE_RELAUNCH_AND_POWERWASH" desc="The label for the  button that relaunches and powerwashes the browser once update is complete">
+      Relaunch and Powerwash
+    </message>
     <message name="IDS_SETTINGS_UPGRADE_UPDATING" desc="Status label: Updating ChromiumOS or ChromeOS">
       Updating your device
     </message>
     <message name="IDS_SETTINGS_UPGRADE_SUCCESSFUL_RELAUNCH" desc="Status label: Successfully updated ChromiumOS/ChromeOS">
       Nearly up-to-date! Restart your device to finish updating.
     </message>
     <message name="IDS_SETTINGS_UPGRADE_UPDATING_CHANNEL_SWITCH" desc="Status label: Updating ChromiumOS/ChromeOS to a specified channel">
       Updating your device to <ph name="CHANNEL_NAME">$1<ex>stable</ex></ph> channel
     </message>
     <message name="IDS_SETTINGS_UPGRADE_SUCCESSFUL_CHANNEL_SWITCH" desc="Status label: Channel was successfully switched on ChromiumOS/ChromeOS">
       Channel changed. Restart your device to apply changes.
     </message>
     <message name="IDS_SETTINGS_UPGRADE_UP_TO_DATE" desc="Status label: Already up to date (ChromiumOS/ChromeOS)">
       Your <ph name="DEVICE_TYPE">$1<ex>Chromebook</ex></ph> is up to date.
     </message>
   </if>
+  <if expr="not chromeos">
+    <message name="IDS_SETTINGS_ABOUT_PAGE_RELAUNCH" desc="The label for the relaunch button that relaunches the browser once update is complete">
+      Relaunch
+    </message>
+  </if>
   <if expr="_google_chrome">
     <message name="IDS_SETTINGS_ABOUT_PAGE_REPORT_AN_ISSUE" desc="Text of the button which allows the user to report an issue with Chrome.">
       Report an issue
     </message>
   </if>
   <message name="IDS_SETTINGS_ABOUT_UPGRADE_CHECK_STARTED" desc="Status label: About to start checking for updates">
     Checking for updates
   </message>
 
   <!-- Policy Indicators -->
@@ skipping 1301 matching lines @@
       System
     </message>
     <message name="IDS_SETTINGS_SYSTEM_HARDWARE_ACCELERATION_LABEL" desc="Label for the checkbox that forces Chrome to render via hardware acceleration (GPU) when available.">
       Use hardware acceleration when available
     </message>
     <message name="IDS_SETTINGS_SYSTEM_PROXY_SETTINGS_BUTTON" desc="Text for the button that changes a user's network proxy settings.">
       Change proxy settings
     </message>
   </if>
 </grit-part>