support animated GIF

ui/file_manager/gallery/js/image_editor/filter.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.
 
 /**
  * A namespace for image filter utilities.
  */
 var filter = {};
 
 /**
@@ skipping 13 matching lines @@
     ImageUtil.trace.report(name, Math.round(mPixPerSec * 10) / 10 + 'Mps');
   }
 };
 
 /**
  * Apply a filter to a image by splitting it into strips.
  *
  * To be used with large images to avoid freezing up the UI.
  *
  * @param {!HTMLCanvasElement} dstCanvas Destination canvas.
- * @param {!HTMLCanvasElement} srcCanvas Source canvas.
+ * @param {!HTMLCanvasElement|!HTMLImageElement} srcImage Source image.
  * @param {function(!ImageData,!ImageData,number,number)} filterFunc Filter.
  * @param {function(number, number)} progressCallback Progress callback.
  * @param {number=} opt_maxPixelsPerStrip Pixel number to process at once.
  */
 filter.applyByStrips = function(
-    dstCanvas, srcCanvas, filterFunc, progressCallback, opt_maxPixelsPerStrip) {
+    dstCanvas, srcImage, filterFunc, progressCallback, opt_maxPixelsPerStrip) {
   // 1 Mpix is a reasonable default.
   var maxPixelsPerStrip = opt_maxPixelsPerStrip || 1000000;
 
   var dstContext = dstCanvas.getContext('2d');
-  var srcContext = srcCanvas.getContext('2d');
-  var source = srcContext.getImageData(0, 0, srcCanvas.width, srcCanvas.height);
+  var srcContext = ImageUtil.ensureCanvas(srcImage).getContext('2d');
+  var source = srcContext.getImageData(0, 0, srcImage.width, srcImage.height);
 
-  var stripCount = Math.ceil(srcCanvas.width * srcCanvas.height /
+  var stripCount = Math.ceil(srcImage.width * srcImage.height /
       maxPixelsPerStrip);
 
   var strip = srcContext.getImageData(0, 0,
-      srcCanvas.width, Math.ceil(srcCanvas.height / stripCount));
+      srcImage.width, Math.ceil(srcImage.height / stripCount));
 
   var offset = 0;
 
   function filterStrip() {
     // If the strip overlaps the bottom of the source image we cannot shrink it
     // and we cannot fill it partially (since canvas.putImageData always draws
     // the entire buffer).
     // Instead we move the strip up several lines (converting those lines
     // twice is a small price to pay).
     if (offset > source.height - strip.height) {
@@ skipping 547 matching lines @@
 /**
  * @param {{r: !Array<number>, g: !Array<number>, b: !Array<number>}}
  *     histogram
  * @return {boolean} True if the autofix would make a visible difference.
  */
 filter.autofix.isApplicable = function(histogram) {
   return filter.autofix.needsStretching(histogram.r) ||
          filter.autofix.needsStretching(histogram.g) ||
          filter.autofix.needsStretching(histogram.b);
 };