arc: Handle ARC events in MD Settings

chrome/browser/resources/settings/android_apps_page/android_apps_browser_proxy.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview A helper object used by the "Google Play Store" (ARC) section
  * to retrieve information about android apps.
  */
 
 /**
- * @typedef {{appReady: boolean}}
+/**
+ * @typedef {{
+ *   playStoreEnabled: boolean,
+ *   appSettingsAvailable: boolean,

[stevenjb, 2017/05/10 16:47:03]

nit: document each of these. I know we use 'Play Store' for the user facing
messaging, but I still think of the feature availability as 'ARC'.
also: maybe 'settingsAppAvailable'?

[khmel, 2017/05/10 21:48:12]

Some times ago we changed meaning ARC available to Play Store available. There 
is current work to use ARC without the Play Store and we distinguish Play Store
and ARC availability.  Also renamed.

+ * }}
  * @see chrome/browser/ui/webui/settings/chromeos/android_apps_handler.cc
  */
 var AndroidAppsInfo;
 
 cr.define('settings', function() {
   /** @interface */
   function AndroidAppsBrowserProxy() {
   }
 
   AndroidAppsBrowserProxy.prototype = {
@@ skipping 27 matching lines @@
     showAndroidAppsSettings: function(keyboardAction) {
       chrome.send('showAndroidAppsSettings', [keyboardAction]);
     },
   };
 
   return {
     AndroidAppsBrowserProxy: AndroidAppsBrowserProxy,
     AndroidAppsBrowserProxyImpl: AndroidAppsBrowserProxyImpl,
   };
 });