[fsp] Introduce chrome://fsp-internals for logging and debugging.

chrome/browser/resources/chromeos/fsp_internals.js

+// Copyright 2014 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.
+
+<include src="../../../../third_party/polymer/platform/platform.js">
+<include src="../../../../third_party/polymer/polymer/polymer.js">
+
+// Define the file-systems element.
+Polymer('file-systems', {
+  ready: function() {
+  },
+
+  /**
+   * List of provided file system information maps.
+   * @type {Array.<Object>}
+   */
+   model: []
+});
+
+/*
+ * Updates the mounted file system list.
+ * @param {Object} fileSystems Dictionary containing provided file system
+ *     information.
+ *
+ */
+function updateFileSystems(fileSystems) {
+  var mountedFileSystems = document.querySelector('#mounted-file-systems');
+  mountedFileSystems.model = fileSystems;
+  Platform.performMicrotaskCheckpoint();
+}
+
+document.addEventListener('DOMContentLoaded', function() {
+  chrome.send('updateFileSystems');
+
+  // Refresh periodically.
+  setInterval(function() {
+    chrome.send('updateFileSystems');
+  }, 1000);
+});