[AudioPlayer] Implement shuffle mode

chrome/browser/resources/file_manager/audio_player/elements/audio_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.
 
 'use strict';
 
 Polymer('audio-player', {
   /**
    * Child Elements
    */
@@ skipping 112 matching lines @@
     if (this.audioElement.readyState !== 0)
       this.audioElement.currentTime = this.audioController.time / 1000;
   },
 
   /**
    * Invoked when audioController.shuffle is changed.
    * @param {boolean} oldValue old value.
    * @param {boolean} newValue new value.
    */
   onControllerShuffleChanged: function(oldValue, newValue) {
-    // TODO(yoshiki): Implement shuffle mode.
+    this.trackList.shuffle = newValue;
   },
 
   /**
    * Invoked when audioController.repeat is changed.
    * @param {boolean} oldValue old value.
    * @param {boolean} newValue new value.
    */
   onControllerRepeatChanged: function(oldValue, newValue) {
     this.trackList.repeat = newValue;
   },
@@ skipping 43 matching lines @@
 
   /**
    * Goes to the previous or the next track.
    * @param {boolean} forward True if next, false if previous.
    * @param {boolean} repeat True if repeat-mode is enabled. False otherwise.
    * @private
    */
   advance_: function(forward, repeat) {
     this.cancelAutoAdvance_();
 
-    var nextTrackIndex = this.trackList.getNextTrackIndex(forward);
-    var nextTrack = this.trackList.tracks[nextTrackIndex];
-    var isNextTrackAvailable = this.trackList.isNextTrackAvailable(forward);
+    var nextTrackIndex = this.trackList.getNextTrackIndex(forward, true);
+    var isNextTrackAvailable =
+        (this.trackList.getNextTrackIndex(forward, repeat) !== -1);
 
     this.trackList.currentTrackIndex = nextTrackIndex;
 
-    if (isNextTrackAvailable || repeat && nextTrack) {
+    if (isNextTrackAvailable) {
+      var nextTrack = this.trackList.tracks[nextTrackIndex];
       this.audioElement.src = nextTrack.url;
       this.audioElement.play();
     } else {
       this.audioElement.pause();
     }
   },
 
   /**
    * Timeout ID of auto advance. Used internally in scheduleAutoAdvance_() and
    *     cancelAutoAdvance_().
@@ skipping 86 matching lines @@
     this.audioController.playlistExpanded = !!expand;
   },
 
   /**
    * Invoked when the audio player is being unloaded.
    */
   onPageUnload: function() {
     this.audioElement.src = '';  // Hack to prevent crashing.
   },
 });