Propagate the result of AmountOfFreeSpace to JS and show it in chrome://drive-internals.

chrome/browser/resources/chromeos/drive_internals.js

 // Copyright (c) 2012 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.
 
 /**
  * Updates the Authentication Status section.
  * @param {Object} authStatus Dictionary containing auth status.
  */
 function updateAuthStatus(authStatus) {
   $('has-refresh-token').textContent = authStatus['has-refresh-token'];
@@ skipping 51 matching lines @@
   tr.appendChild(createElementFromText('td', cacheEntry.is_present));
   tr.appendChild(createElementFromText('td', cacheEntry.is_pinned));
   tr.appendChild(createElementFromText('td', cacheEntry.is_dirty));
   tr.appendChild(createElementFromText('td', cacheEntry.is_mounted));
   tr.appendChild(createElementFromText('td', cacheEntry.is_persistent));
 
   $('cache-contents').appendChild(tr);
 }
 
 /**
+ * Updates the Local Storage summary.
+ * @param {Object} localStorageSummary Dictionaty describing the status of local
+ * stogage.
+ */
+function updateLocalStorageUsage(localStorageSummary) {
+  var freeSpaceInMB = localStorageSummary.free_space / (1 << 20);
+  $('local-storage-freespace').innerText = freeSpaceInMB;
+}
+
+/**
  * Creates an element named |elementName| containing the content |text|.
  * @param {string} elementName Name of the new element to be created.
  * @param {string} text Text to be contained in the new element.
  * @return {HTMLElement} The newly created HTML element.
  */
 function createElementFromText(elementName, text) {
   var element = document.createElement(elementName);
   element.appendChild(document.createTextNode(text));
   return element;
 }
 
 document.addEventListener('DOMContentLoaded', function() {
   chrome.send('pageLoaded');
 });