Remove file-level 'use strict' from file_manager.

ui/file_manager/image_loader/image_loader_client.js

 // Copyright 2013 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';
-
 /**
  * Client used to connect to the remote ImageLoader extension. Client class runs
  * in the extension, where the client.js is included (eg. Files.app).
  * It sends remote requests using IPC to the ImageLoader class and forwards
  * its responses.
  *
  * Implements cache, which is stored in the calling extension.
  *
  * @constructor
  */
@@ skipping 343 matching lines @@
       onError();
       return;
     }
     image.src = result.data;
     onSuccess();
   };
 
   return ImageLoaderClient.getInstance().load(
       url, callback, options, opt_isValid);
 };