Introduce Image loader extension.

chrome/browser/resources/file_manager/js/file_selection.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.
 
 /**
  * The current selection object.
  *
  * @param {FileManager} fileManager FileManager instance.
  * @param {Array.<number>} indexes Selected indexes.
  * @constructor
@@ skipping 579 matching lines @@
  * @param {Function} callback Callend when image loaded.
  * @return {HTMLDivElement} Created element.
  * @private
  */
 FileSelectionHandler.prototype.renderThumbnail_ = function(entry, callback) {
   var thumbnail = this.fileManager_.document_.createElement('div');
   FileGrid.decorateThumbnailBox(thumbnail,
                                 entry,
                                 this.fileManager_.metadataCache_,
                                 ThumbnailLoader.FillMode.FILL,
+                                ThumbnailLoader.OptimizationMode.NEVER_DISCARD,
                                 callback);
   return thumbnail;
 };
 
 /**
  * Updates the search breadcrumbs.
  *
  * @private
  */
 FileSelectionHandler.prototype.updateSearchBreadcrumbs_ = function() {
@@ skipping 77 matching lines @@
   style.left = (boxWidth - imageWidth) / 2 + 'px';
   style.top = (boxHeight - imageHeight) / 2 + 'px';
   style.position = 'relative';
 
   util.applyTransform(largeImage, transform);
 
   largeImageBox.appendChild(largeImage);
   largeImageBox.style.zIndex = 1000;
   return true;
 };