[Not committed] Make image load completion async and remove EventSender from ImageLoader

third_party/WebKit/LayoutTests/svg/canvas/image-svg-intrinsic-size.html

Index: third_party/WebKit/LayoutTests/svg/canvas/image-svg-intrinsic-size.html
diff --git a/third_party/WebKit/LayoutTests/svg/canvas/image-svg-intrinsic-size.html b/third_party/WebKit/LayoutTests/svg/canvas/image-svg-intrinsic-size.html
index 917e029e8d7bc744e85d2d0cdfc37fd3f282a9fe..6c4c77c77b15ba4bc5cdb2949c6738b50aa835b9 100644
--- a/third_party/WebKit/LayoutTests/svg/canvas/image-svg-intrinsic-size.html
+++ b/third_party/WebKit/LayoutTests/svg/canvas/image-svg-intrinsic-size.html
@@ -5,15 +5,18 @@
   function createSVGImage() {
       var image = document.createElement('img');
       image.style.width = "5px";
+      image.onload = imageOnLoad;
       image.src = "data:image/svg+xml," +
                   "<svg xmlns='http://www.w3.org/2000/svg' width='200' viewBox='0 0 1 1'>" +
                   "<rect width='1' height='1' fill='green'/></svg>";
       return image;
   }
   document.body.appendChild(createSVGImage());
-  document.body.offsetTop; // Force layout
-  var canvas = document.querySelector('canvas');
-  var ctx = canvas.getContext("2d");
-  ctx.drawImage(document.querySelector('img'), 0, 0);
-  document.body.removeChild(document.querySelector('img'));
+  function imageOnLoad() {
+      document.body.offsetTop; // Force layout
+      var canvas = document.querySelector('canvas');
+      var ctx = canvas.getContext("2d");
+      ctx.drawImage(document.querySelector('img'), 0, 0);
+      document.body.removeChild(document.querySelector('img'));
+  }
 </script>