Audio Player: Add support for Media Keys

ui/file_manager/file_manager/audio_player/elements/audio_player.js

Index: ui/file_manager/file_manager/audio_player/elements/audio_player.js
diff --git a/ui/file_manager/file_manager/audio_player/elements/audio_player.js b/ui/file_manager/file_manager/audio_player/elements/audio_player.js
index eb9600c4016cc184b3fcd6b26ee54edfd8a6194c..4ddd4346d2fc5374de992e00c8e18bd42aad9f5d 100644
--- a/ui/file_manager/file_manager/audio_player/elements/audio_player.js
+++ b/ui/file_manager/file_manager/audio_player/elements/audio_player.js
@@ -339,6 +339,19 @@ Polymer('audio-player', {
         if (this.audioController.volumeSliderShown && this.model.volume > 9)
           this.model.volume -= 10;
         break;
+      case 'MediaNextTrack':
+        this.onControllerNextClicked();
+        break;
+      case 'MediaPlayPause':
+        var playing = this.audioController.playing;
+        this.onControllerPlayingChanged(playing, !playing);
+        break;
+      case 'MediaPreviousTrack':
+        this.onControllerPreviousClicked();
+        break;
+      case 'MediaStop':
+        // TODO: Define "Stop" behavior.
+        break;
     }
   },
 });