Remove file-level 'use strict' from file_manager.

ui/file_manager/video_player/js/error_util.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';
-
 /**
  * This variable is checked in SelectFileDialogExtensionBrowserTest.
  * @type {number}
  */
 window.JSErrorCount = 0;
 
 /**
  * Counts uncaught exceptions.
  */
 window.onerror = function() { window.JSErrorCount++; };
@@ skipping 24 matching lines @@
       // the exception message and stack trace just in case.
       // The message will show twice if the caller handles exception correctly.
       console.error(e.stack);
       console.info('Exception above happened in callback.', liveStack);
 
       window.JSErrorCount++;
       throw e;
     }
   }
 };