Deflake repaint layout tests which assumed scroll would happen before first paint.

LayoutTests/fast/repaint/resources/text-based-repaint.js

Index: LayoutTests/fast/repaint/resources/text-based-repaint.js
diff --git a/LayoutTests/fast/repaint/resources/text-based-repaint.js b/LayoutTests/fast/repaint/resources/text-based-repaint.js
index c85bb11c258f7a8303da774562a64d87e6ee3cad..4a0b96601c1fc63e8ffa08862143c508190ae7d6 100644
--- a/LayoutTests/fast/repaint/resources/text-based-repaint.js
+++ b/LayoutTests/fast/repaint/resources/text-based-repaint.js
@@ -51,6 +51,17 @@ function runRepaintAndPixelTest()
     runRepaintTest();
 }
 
+function runAfterDisplay(callback)
+{
+    if (!window.testRunner) {
+        setTimeout(callback, 500);
+    } else {
+        testRunner.waitUntilDone();
+        testRunner.displayAsyncThen(callback);
+    }
+

[Xianzhu, 2014/12/12 16:42:00]

Nit: remove this line.

[rmcilroy, 2014/12/12 17:20:17]

Done.

+}
+
 function forceStyleRecalc()
 {
     if (document.body)