[POC-WIP] Link window focus tokens with ExecutionContext.

Source/modules/serviceworkers/WaitUntilObserver.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "modules/serviceworkers/WaitUntilObserver.h"
 
 #include "bindings/core/v8/ScriptFunction.h"
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptValue.h"
@@ skipping 116 matching lines @@
     WebServiceWorkerEventResult result = m_hasError ? WebServiceWorkerEventResultRejected : WebServiceWorkerEventResultCompleted;
     switch (m_type) {
     case Activate:
         client->didHandleActivateEvent(m_eventID, result);
         break;
     case Install:
         client->didHandleInstallEvent(m_eventID, result);
         break;
     case NotificationClick:
         client->didHandleNotificationClickEvent(m_eventID, result);
+        executionContext()->consumeWindowFocusToken();
         break;
     case Push:
         client->didHandlePushEvent(m_eventID, result);
         break;
     }
     observeContext(0);
 }
 
 } // namespace blink