Refactor of various layout tests to use RAF

LayoutTests/svg/repaint/image-with-clip-path.svg

Index: LayoutTests/svg/repaint/image-with-clip-path.svg
diff --git a/LayoutTests/svg/repaint/image-with-clip-path.svg b/LayoutTests/svg/repaint/image-with-clip-path.svg
index b801db7e7a35600d8865f857710fb62a2df9de55..ea6a16895e3fb5a9c8c1660275875eee171308ab 100644
--- a/LayoutTests/svg/repaint/image-with-clip-path.svg
+++ b/LayoutTests/svg/repaint/image-with-clip-path.svg
@@ -31,12 +31,17 @@
     }
 
     function nextStep() {
-        i.onload = function() { setTimeout(finishTest, 0); };
+        i.onload = function() { requestAnimationFrame(finishTest); };
         update(200, 50, green);
     }
 
     function repaintTest() {
-        i.onload = function() { setTimeout(nextStep, 0); };
+        // Nested RAF to ensure enough time elapsed for repaint logging to occur
+        i.onload = function() {
+            requestAnimationFrame(function() {
+                requestAnimationFrame(nextStep);
+            });
+        };
         update(50, 100, red);
     }
 </script>