Increase repaint test delay when running in browser

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

 // Asynchronous tests should manually call finishRepaintTest at the appropriate
 // time.
 window.testIsAsync = false;
 window.outputRepaintRects = true;
 
 function runRepaintTest()
 {
     if (!window.testRunner || !window.internals) {
-        setTimeout(repaintTest, 100);
+        setTimeout(repaintTest, 500);
         return;
     }
 
     // TODO(enne): this is a workaround for multiple svg onload events.
     // See: http://crbug.com/372946
     if (window.hasRunRepaintTest)
         return;
     window.hasRunRepaintTest = true;
 
     if (window.enablePixelTesting)
@@ skipping 42 matching lines @@
     if (window.outputRepaintRects)
         testRunner.setCustomTextOutput(repaintRects);
 
     if (window.afterTest)
         window.afterTest();
 
     // Play nice with async JS tests which want to notifyDone themselves.
     if (!window.jsTestIsAsync)
         testRunner.notifyDone();
 }