Increase repaint test delay when running in browser

When running a repaint test in browser, sometimes we may want to see
the page contents before and after repaintTest(). The origianl 100ms
delay seems too short to show the page contents before repaintTest().

This may be more useful when we have repaint overlay feature when
showing layout test results (https://codereview.chromium.org/303223008/).

Review URL: https://codereview.chromium.org/304273005

git-svn-id: svn://svn.chromium.org/blink/trunk@175165 bbb929c8-8fbe-4397-9dbb-9b2b20218538

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

@@ -6,7 +6,7 @@ window.outputRepaintRects = true;
 function runRepaintTest()
 {
     if (!window.testRunner || !window.internals) {
-        setTimeout(repaintTest, 100);
+        setTimeout(repaintTest, 500);
         return;
     }