Revert of AudioPlayer: Update volume controls.

ui/file_manager/audio_player/elements/audio_player.js

Index: ui/file_manager/audio_player/elements/audio_player.js
diff --git a/ui/file_manager/audio_player/elements/audio_player.js b/ui/file_manager/audio_player/elements/audio_player.js
index a050d3cbdb5d55e8292a1157066a5176e5fc274a..7b6cab4d7cfd521fa08d9c5739709061ef579766 100644
--- a/ui/file_manager/audio_player/elements/audio_player.js
+++ b/ui/file_manager/audio_player/elements/audio_player.js
@@ -57,14 +57,6 @@
     },
 
     /**
-     * Whether the volume slider is shown.
-     */
-    volumeSliderShown: {
-      type: Boolean,
-      observer: 'volumeSliderShownChanged'
-    },
-
-    /**
      * Track index of the current track.
      */
     currentTrackIndex: {
@@ -140,14 +132,6 @@
   expandedChanged: function(expanded) {
     if (this.model)
       this.model.expanded = expanded;
-  },
-
-  /**
-   * Handles change event for volumeSliderShown state.
-   */
-  volumeSliderShownChanged: function(volumeSliderShown) {
-    if (this.model)
-      this.model.volumeSliderShown = volumeSliderShown;
   },
 
   /**
@@ -238,7 +222,6 @@
       this.repeat = newModel.repeat;
       this.volume = newModel.volume;
       this.expanded = newModel.expanded;
-      this.volumeSliderShown = newModel.volumeSliderShown;
     }
   },