Audio Player: Notify track metadata update to track-list element explicitly.

ui/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.
 
 Polymer({
   is: 'audio-player',
 
   properties: {
     /**
      * Flag whether the audio is playing or paused. True if playing, or false
@@ skipping 331 matching lines @@
 
     this.$.trackList.tracks = tracks;
     var currentTrack = this.$.trackList.getCurrentTrack();
     if (currentTrack && currentTrack.url != this.$.audio.src) {
       this.$.audio.src = currentTrack.url;
       this.$.audio.play();
     }
   },
 
   /**
+   * Notifis the track-list element that the metadata for specified track is
+   * updated.
+   * @param {number} index The index of the track whose metadata is updated.
+   */
+  notifyTrackMetadataUpdated: function(index) {

[yoshiki, 2016/01/14 11:10:27]

nit: should we check if the argument is valid just in case? 

[fukino, 2016/01/14 11:32:35]

Added a check for index range. Done.

+    this.$.trackList.notifyPath('tracks.' + index + '.title',
+        this.tracks[index].title);
+    this.$.trackList.notifyPath('tracks.' + index + '.artist',
+        this.tracks[index].artist);
+  },
+
+  /**
    * Invoked when the audio player is being unloaded.
    */
   onPageUnload: function() {
     this.$.audio.src = '';  // Hack to prevent crashing.
   },
 
   /**
    * Invoked when dragging state of seek bar on control panel is changed.
    * During the user is dragging it, audio playback is paused temporalily.
    */
@@ skipping 34 matching lines @@
 
   /**
    * Computes volume value for audio element. (should be in [0.0, 1.0])
    * @param {number} volume Volume which is set in the UI. ([0, 100])
    * @return {number}
    */
   computeAudioVolume_: function(volume) {
     return volume / 100;
   }
 });