Adds histograms for casting feature of Video Player

ui/file_manager/video_player/js/video_player.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.
 
 /**
  * @param {Element} playerContainer Main container.
  * @param {Element} videoContainer Container for the video element.
  * @param {Element} controlsContainer Container for video controls.
  * @constructor
  */
@@ skipping 300 matching lines @@
             document.querySelector('#thumbnail').style.backgroundImage = '';
           }
         })
         .catch(function() {
           // Shows no image on error.
           document.querySelector('#thumbnail').style.backgroundImage = '';
         });
 
     var videoElementInitializePromise;
     if (this.currentCast_) {
+      metrics.recordPlayType(metrics.PLAY_TYPE.CAST);
+
       videoPlayerElement.setAttribute('casting', true);
 
       document.querySelector('#cast-name').textContent =
           this.currentCast_.friendlyName;
 
       videoPlayerElement.setAttribute('castable', true);
 
       videoElementInitializePromise = media.isAvailableForCast()
           .then(function(result) {
             if (!result)
               return Promise.reject('No casts are available.');
 
             return new Promise(function(fulfill, reject) {
               chrome.cast.requestSession(
                   fulfill, reject, undefined, this.currentCast_.label);
             }.bind(this)).then(function(session) {
               session.addUpdateListener(this.onCastSessionUpdateBound_);
 
               this.currentSession_ = session;
               this.videoElement_ = new CastVideoElement(media, session);
               this.controls.attachMedia(this.videoElement_);
             }.bind(this));
           }.bind(this));
     } else {
+      metrics.recordPlayType(metrics.PLAY_TYPE.LOCAL);
       videoPlayerElement.removeAttribute('casting');
 
       this.videoElement_ = document.createElement('video');
       document.querySelector('#video-container').appendChild(
           this.videoElement_);
 
       this.controls.attachMedia(this.videoElement_);
       this.videoElement_.src = video.url;
 
       media.isAvailableForCast().then(function(result) {
@@ skipping 28 matching lines @@
           }.wrap());
           this.videoElement_.addEventListener('pause', function() {
             chrome.power.releaseKeepAwake();
           }.wrap());
 
           this.videoElement_.load();
           callback();
         }.bind(this))
         // In case of error.
         .catch(function(error) {
+          if (this.currentCast_)
+            metrics.recordCastVideoErrorAction();
+
           videoPlayerElement.removeAttribute('loading');
           console.error('Failed to initialize the video element.',
                         error.stack || error);
           this.controls_.showErrorMessage(
               'VIDEO_PLAYER_VIDEO_FILE_UNSUPPORTED');
           callback();
         }.bind(this));
   }.wrap(this));
 };
 
@@ skipping 258 matching lines @@
   }.wrap(null));
 }
 
 var initPromise = Promise.all(
     [new Promise(initVideos.wrap(null)),
      new Promise(initStrings.wrap(null)),
      new Promise(util.addPageLoadHandler.wrap(null))]);
 
 initPromise.then(function(results) {
   var videos = results[0];
+
+  metrics.recordOpenVideoPlayerAction();
+  metrics.recordNumberOfOpenedFiles(videos.length);
+
   player.prepare(videos);
   return new Promise(player.playFirstVideo.wrap(player));
 }.wrap(null));