Worker: Wait for termination by WorkerThreadLifecycleObserver instead of WaitableEvent

third_party/WebKit/Source/core/workers/WorkerThread.h

Index: third_party/WebKit/Source/core/workers/WorkerThread.h
diff --git a/third_party/WebKit/Source/core/workers/WorkerThread.h b/third_party/WebKit/Source/core/workers/WorkerThread.h
index 76c05fb3705ec9abc833b1f6d48f3f30416a3cb5..2bf6cee53d760d4c10d82493ef5d26bf5b0e098c 100644
--- a/third_party/WebKit/Source/core/workers/WorkerThread.h
+++ b/third_party/WebKit/Source/core/workers/WorkerThread.h
@@ -114,11 +114,6 @@ public:
     virtual bool shouldAttachThreadDebugger() const { return true; }
     v8::Isolate* isolate();
 
-    // Can be used to wait for this worker thread to terminate.
-    // (This is signaled on the main thread, so it's assumed to be waited on
-    // the worker context thread)
-    WaitableEvent* terminationEvent() { return m_terminationEvent.get(); }
-
     bool isCurrentThread();
 
     WorkerLoaderProxy* workerLoaderProxy() const
@@ -239,9 +234,6 @@ private:
     Persistent<WorkerOrWorkletGlobalScope> m_globalScope;
     Persistent<WorkerInspectorController> m_workerInspectorController;
 
-    // Signaled when the thread starts termination on the main thread.
-    std::unique_ptr<WaitableEvent> m_terminationEvent;
-
     // Signaled when the thread completes termination on the worker thread.
     std::unique_ptr<WaitableEvent> m_shutdownEvent;