Add ServiceWorker InstallPhaseEvent.waitUntil() layout test.

LayoutTests/http/tests/serviceworker/request-end-to-end.html

Index: LayoutTests/http/tests/serviceworker/request-end-to-end.html
diff --git a/LayoutTests/http/tests/serviceworker/request-end-to-end.html b/LayoutTests/http/tests/serviceworker/request-end-to-end.html
index 4e5f4656317f52852c605b8cbc377d7d78acee4a..83acdda6a69c5e3c86fbcc70a643d834e5569210 100644
--- a/LayoutTests/http/tests/serviceworker/request-end-to-end.html
+++ b/LayoutTests/http/tests/serviceworker/request-end-to-end.html
@@ -24,7 +24,7 @@ t.step(function() {
         }), false);
         port.start();
         sw.addEventListener('statechange', t.step_func(function(event) {
-            if (event.target.state == 'active')
+            if (event.target.state == 'activated')
                 onActive();
         }));
     }