Add ServiceWorker InstallPhaseEvent.waitUntil() layout test.

LayoutTests/http/tests/serviceworker/unregister-controller.html

Index: LayoutTests/http/tests/serviceworker/unregister-controller.html
diff --git a/LayoutTests/http/tests/serviceworker/unregister-controller.html b/LayoutTests/http/tests/serviceworker/unregister-controller.html
index c4cc03308077ea65508054abfc60425339785c61..4716a40075b6516babdbd737f9a915ae4cd1be81 100644
--- a/LayoutTests/http/tests/serviceworker/unregister-controller.html
+++ b/LayoutTests/http/tests/serviceworker/unregister-controller.html
@@ -13,7 +13,7 @@ async_test(function(t) {
     }));
 
     function on_state_change(event) {
-        if (event.target.state != 'active')
+        if (event.target.state != 'activated')
             return;
         with_iframe(scope, t.step_func(function(frame) {
             var w = frame.contentWindow;
@@ -35,7 +35,7 @@ async_test(function(t) {
     }));
 
     function on_state_change(event) {
-        if (event.target.state != 'active')
+        if (event.target.state != 'activated')
             return;
         navigator.serviceWorker.unregister(scope).then(t.step_func(function() {
             with_iframe(scope, t.step_func(function(frame) {