Adds histograms for casting feature of Video Player

ui/file_manager/video_player/js/video_player_metrics.js

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Copyright (c) 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.
 
 /**
  * @fileoverview Utility methods for accessing chrome.metricsPrivate API.
  *
  * To be included as a first script in main.html
  */
 
+/**
+ * @extends {metricsBase}
+ */
 var metrics = metricsBase;
 
-metrics.startInterval('Load.Total');
-metrics.startInterval('Load.Script');
+/**
+ * Values for "VideoPlayer.CastExtensionStaus" metrics.
+ * @enum {number}
+ */
+metrics.CAST_EXTENSION = {
+  EXTENSION_UNAVAILABLE: 0,
+  API_INSTALLATION_FAILED: 1,
+  API_LOAD_FAILED: 2,
+  API_INSTALLED_AND_LOADED: 3,
+  API_AVAILABLE_AND_LOADED: 4,
+  MAX_VALUE: 4
+};
 
 /**
  * Convert a short metric name to the full format.
  *
  * @param {string} name Short metric name.
  * @return {string} Full metric name.
  * @override
  * @private
  */
 metrics.convertName_ = function(name) {
-  return 'FileBrowser.' + name;
+  return 'VideoPlayer.' + name;
 };