Pre-scaling images to speed up feedback in Image Editor.

chrome/browser/resources/file_manager/js/image_editor/image_adjust.js

 // Copyright (c) 2011 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 base class for simple filters that only modify the image content
  * but do not modify the image dimensions.
  */
 ImageEditor.Mode.Adjust = function(displayName, filterFunc) {
   ImageEditor.Mode.call(this, displayName);
   this.filterFunc_ = filterFunc;
 }
 
 ImageEditor.Mode.Adjust.prototype = {__proto__: ImageEditor.Mode.prototype};
 
 ImageEditor.Mode.Adjust.prototype.rollback = function() {
   if (!this.backup_) return; // Did not do anything yet.
-  this.getBuffer().drawImageData(this.backup_);
+  this.getContent().drawImageData(this.backup_, 0, 0);
   this.backup_ = null;
   this.repaint();
 };
 
 ImageEditor.Mode.Adjust.prototype.update = function(options) {
   if (!this.backup_) {
-    this.backup_ = this.getBuffer().copyImageData();
-    this.scratch_ = this.getBuffer().copyImageData();
+    this.backup_ = this.getContent().copyImageData();
+    this.scratch_ = this.getContent().copyImageData();
   }
 
   ImageUtil.trace.resetTimer('filter');
   this.filterFunc_(this.scratch_, this.backup_, options);
   ImageUtil.trace.reportTimer('filter');
-  this.getBuffer().drawImageData(this.scratch_);
+  this.getContent().drawImageData(this.scratch_, 0, 0);
   this.repaint();
 };
 
 /**
  * A simple filter that multiplies every component of a pixel by some number.
  */
 ImageEditor.Mode.Brightness = function() {
   ImageEditor.Mode.Adjust.call(
       this, 'Brightness', ImageEditor.Mode.Brightness.filter);
 }
@@ skipping 33 matching lines @@
   for (var y = 0; y != height; y++) {
     for (var x = 0; x != width; x++ ) {
       dstData[index] = values[srcData[index]]; index++;
       dstData[index] = values[srcData[index]]; index++;
       dstData[index] = values[srcData[index]]; index++;
       dstData[index] = 0xFF; index++;
     }
   }
 };