Let a video resume automatically when changing the playback position after the playback has finished

ui/file_manager/video_player/js/media_controls.js

 // Copyright (c) 2012 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.
 
 /**
  * @fileoverview MediaControls class implements media playback controls
  * that exist outside of the audio/video HTML element.
  */
 
 /**
@@ skipping 327 matching lines @@
   if (!this.media_)
     return;  // Media is detached.
 
   if (!this.media_.seekable || !this.media_.duration) {
     console.error('Inconsistent media state');
     return;
   }
 
   this.setSeeking_(false);
 
+  // Re-start playing the video when the seek bar is moved from ending point.
+  if (this.media_.ended)
+    this.play();
+
   var current = this.media_.duration * value;
   this.media_.currentTime = current;
   this.updateTimeLabel_(current);
 };
 
 /**
  * @private
  */
 MediaControls.prototype.onProgressDrag_ = function() {
   if (!this.media_)
@@ skipping 726 matching lines @@
   } else {
     this.container_.removeAttribute('fullscreen');
   }
 
   if (this.fullscreenButton_) {
     this.fullscreenButton_.setAttribute('aria-label',
         fullscreen ? str('VIDEO_PLAYER_EXIT_FULL_SCREEN_BUTTON_LABEL')
                    : str('VIDEO_PLAYER_FULL_SCREEN_BUTTON_LABEL'));;
   }
 };