Minor improvements to reftests.

sky/tests/harness/reftest-mismatch.sky

Index: sky/tests/harness/reftest-mismatch.sky
diff --git a/sky/tests/harness/reftest-mismatch.sky b/sky/tests/harness/reftest-mismatch.sky
index a016a24f693a457a4f31a582c7945ddca90e6c22..44bcc28f18cc38c3776918e5454f2fb0fbd28282 100644
--- a/sky/tests/harness/reftest-mismatch.sky
+++ b/sky/tests/harness/reftest-mismatch.sky
@@ -1,12 +1,9 @@
 <foo>
+<import src="../resources/run-after-display.sky" as="runAfterDisplay" />
 This is a mismatch reftest. Should not match.
 <script>
-window.addEventListener('load', function() {
-    // TODO(ojan): requestAnimationFrame once we properly pump frames.
-    // https://github.com/domokit/mojo/issues/32
-    setTimeout(function() {
-        internals.notifyTestComplete("");
-    }, 100);
-})
+runAfterDisplay(function() {
+    internals.notifyTestComplete("");
+});
 </script>
 </foo>