Allow creating new windows from a notificationclick event in SW.

Source/modules/serviceworkers/WaitUntilObserver.h

Index: Source/modules/serviceworkers/WaitUntilObserver.h
diff --git a/Source/modules/serviceworkers/WaitUntilObserver.h b/Source/modules/serviceworkers/WaitUntilObserver.h
index 4c70d23d795d8433022156c5a5e96180f477abce..b95e68f69599b9ca9dcf54406afacc03a584bd3c 100644
--- a/Source/modules/serviceworkers/WaitUntilObserver.h
+++ b/Source/modules/serviceworkers/WaitUntilObserver.h
@@ -7,6 +7,7 @@
 
 #include "core/dom/ContextLifecycleObserver.h"
 #include "modules/serviceworkers/ServiceWorkerGlobalScopeClient.h"
+#include "platform/Timer.h"
 #include "wtf/Forward.h"
 #include "wtf/RefCounted.h"
 
@@ -50,11 +51,14 @@ private:
     void incrementPendingActivity();
     void decrementPendingActivity();
 
+    void consumeWindowInteraction(Timer<WaitUntilObserver>*);
+
     EventType m_type;
     int m_eventID;
     int m_pendingActivity;
     bool m_hasError;
     bool m_eventDispatched;
+    Timer<WaitUntilObserver> m_consumeWindowInteractionTimer;
 };
 
 } // namespace blink