import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

dom/html/reftests/toblob-todataurl/blob.js

@@ -0,0 +1,68 @@
+function init() {
+  function end() {
+    document.documentElement.className = '';
+  }
+
+  function next() {
+    compressAndDisplay(original, end);
+  }
+
+  var original = getImageFromDataUrl(sample);
+  setImgLoadListener(original, next);
+}
+
+function compressAndDisplay(image, next) {
+  var canvas = document.createElement('canvas');
+  canvas.width = image.naturalWidth;
+  canvas.height = image.naturalHeight;
+  var ctx = canvas.getContext('2d');
+  ctx.drawImage(image, 0, 0);
+
+  function gotBlob(blob) {
+    var img = getImageFromBlob(blob);
+    setImgLoadListener(img, next);
+    document.body.appendChild(img);
+  }
+
+  // I want to test passing 'undefined' as quality as well
+  if ('quality' in window) {
+    canvas.toBlob(gotBlob, 'image/jpeg', quality);
+  } else {
+    canvas.toBlob(gotBlob, 'image/jpeg');
+  }
+}
+
+function setImgLoadListener(img, func) {
+  if (img.complete) {
+    func.call(img, { target: img});
+  } else {
+    img.addEventListener('load', func);
+  }
+}
+
+function naturalDimensionsHandler(e) {
+  var img = e.target;
+  img.width = img.naturalWidth;
+  img.height = img.naturalHeight;
+}
+
+function getImageFromBlob(blob) {
+  var img = document.createElement('img');
+  img.src = window.URL.createObjectURL(blob);
+  setImgLoadListener(img, naturalDimensionsHandler);
+  setImgLoadListener(img, function(e) {
+    window.URL.revokeObjectURL(e.target.src);
+  });
+
+  return img;
+}
+
+function getImageFromDataUrl(url) {
+  var img = document.createElement('img');
+  img.src = url;
+  setImgLoadListener(img, naturalDimensionsHandler);
+
+  return img;
+}
+
+init();