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

chrome/browser/resources/settings/about_page/about_page.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://md-settings/about_page/about_page_browser_proxy.html">
 <link rel="import" href="chrome://md-settings/i18n_setup.html">
 <link rel="import" href="chrome://md-settings/icons.html">
 <link rel="import" href="chrome://md-settings/settings_page/main_page_behavior.html">
 <link rel="import" href="chrome://md-settings/settings_page/settings_animated_pages.html">
 <link rel="import" href="chrome://md-settings/settings_page/settings_section.html">
 <link rel="import" href="chrome://md-settings/settings_shared_css.html">
 <link rel="import" href="chrome://resources/cr_elements/icons.html">
 <link rel="import" href="chrome://resources/html/i18n_behavior.html">
@@ skipping 50 matching lines @@
                   icon$="[[getIcon_(currentUpdateStatusEvent_)]]"
                   src="[[getIconSrc_(currentUpdateStatusEvent_)]]">
               </iron-icon>
             </div>
             <div class="start">
               <div hidden="[[!shouldShowUpdateStatus_(currentUpdateStatusEvent_)]]">
                 [[getUpdateStatusMessage_(currentUpdateStatusEvent_)]]
               </div>
               <div class="secondary">$i18n{aboutBrowserVersion}</div>
             </div>
+            <paper-button id="relaunch" class="secondary-action"
+                hidden="[[!shouldShowRelaunch_(currentUpdateStatusEvent_)]]"
+                on-tap="onRelaunchTap_">
+              $i18n{aboutRelaunch}
+            </paper-button>
 <if expr="chromeos">
-            <paper-button class="secondary-action">Check for update</paper-button>
+            <paper-button id="relaunchAndPowerwash" class="secondary-action"
+                hidden="[[!shouldShowRelaunchAndPowerwash_(currentUpdateStatusEvent_)]]"
+                on-tap="onRelaunchAndPowerwashTap_">
+              $i18n{aboutRelaunchAndPowerwash}
+            </paper-button>
+            <paper-button id="checkForUpdates" class="secondary-action"
+                hidden="[[!shouldShowCheckUpdates_(currentUpdateStatusEvent_)]]"
+                on-tap="onCheckUpdatesTap_">
+              $i18n{aboutCheckForUpdates}
+            </paper-button>
 </if>
           </div>
           <div id="help" class="settings-box two-line" on-tap="onHelpTap_">
             $i18n{aboutGetHelpUsingChrome}
           </div>
 <if expr="_google_chrome">
           <div id="reportIssue" class="settings-box" on-tap="onReportIssueTap_">
             $i18n{aboutReportAnIssue}
           </div>
 </if>
 <if expr="chromeos">
           <div class="settings-box" on-tap="onDetailedBuildInfoTap_">
             <!-- TODO(dpapad): Localize string. -->
             Detailed build info
           </div>
 </if>
         </neon-animatable>
 <if expr="chromeos">
         <template is="dom-if" name="detailed-build-info">
           <settings-subpage page-title="Detailed build information">
             <settings-detailed-build-info></settings-detailed-build-info>
           </settings-subpage>
         </template>
 </if>
       </settings-animated-pages>
     </settings-section>
   </template>
   <script src="about_page.js"></script>
 </dom-module>