Storage manager: Show overall size information and size of Downloads.

chrome/browser/resources/options/chromeos/storage_manager.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.
 
+/**
+ * @typedef {{
+ *   totalSize: string,
+ *   availableSize: string,
+ *   usedSize: string,
+ *   usedRatio: number
+ * }}
+ */
+options.StorageSizeStat;
+
 cr.define('options', function() {
   var Page = cr.ui.pageManager.Page;
   var PageManager = cr.ui.pageManager.PageManager;
 
   function StorageManager() {
     Page.call(this, 'storage',
               loadTimeData.getString('storageManagerPageTabTitle'),
               'storageManagerPage');
   }
 
   cr.addSingletonGetter(StorageManager);
 
   StorageManager.prototype = {
     __proto__: Page.prototype,
 
     /** @override */
     initializePage: function() {
       Page.prototype.initializePage.call(this);
 
+      $('storage-manager-label-downloads').onclick = function() {
+        chrome.send('openDownloads');
+      };
+
       $('storage-confirm').onclick = function() {
         PageManager.closeOverlay();
       };
-    }
+    },
+
+    /** @override */
+    didShowPage: function() {
+      // Updating storage information can be expensive (e.g. computing directory
+      // sizes recursively), so we delay this operation until the page is shown.
+      chrome.send('updateStorageInfo');
+    },
+
+    /**
+     * Updates the size information (total/used/available) of the internal
+     * storage.
+     * @param {!options.StorageSizeStat} sizeStat
+     * @private
+     */
+    setSizeStat_: function(sizeStat) {
+      $('storage-manager-size-capacity').textContent = sizeStat.totalSize;
+      $('storage-manager-size-in-use').textContent = sizeStat.usedSize;
+      $('storage-manager-size-available').textContent = sizeStat.availableSize;
+    },
+
+    /**
+     * Updates the size Downloads directory.
+     * @param {string} size Formatted string of the size of Downloads.
+     * @private
+     */
+    setDownloadsSize_: function(size) {
+      $('storage-manager-size-downloads').textContent = size;
+    },
   };
 
+  // Forward public APIs to private implementations.
+  cr.makePublic(StorageManager, [
+    'setSizeStat',
+    'setDownloadsSize',
+  ]);
+
   return {
     StorageManager: StorageManager
   };
 });