Expose Web Animations API to Web Workers

Source/core/workers/WorkerMessagingProxy.cpp

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  * Copyright (C) 2009 Google Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 285 matching lines @@
 void WorkerMessagingProxy::reportPendingActivity(bool hasPendingActivity)
 {
     m_workerThreadHadPendingActivity = hasPendingActivity;
 }
 
 bool WorkerMessagingProxy::hasPendingActivity() const
 {
     return (m_unconfirmedMessageCount || m_workerThreadHadPendingActivity) && !m_askedToTerminate;
 }
 
+WorkerGlobalScope * WorkerMessagingProxy::extractWorkerGlobalScope()
+{
+    if (m_workerThread) {
+        return m_workerThread->workerGlobalScope();
+    }
+    return nullptr;
+}
+
 } // namespace blink