Worker: Introduce an observation mechanism for WorkerThread termination

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 92c7dbe30e5e2029efd02695376b526fe3649d85..9c3c9bec643250c643eaecdc737a896cf31d4e08 100644
--- a/third_party/WebKit/Source/core/workers/WorkerThread.h
+++ b/third_party/WebKit/Source/core/workers/WorkerThread.h
@@ -32,6 +32,7 @@
 #include "core/frame/csp/ContentSecurityPolicy.h"
 #include "core/workers/WorkerGlobalScope.h"
 #include "core/workers/WorkerLoaderProxy.h"
+#include "core/workers/WorkerThreadLifecycleObserver.h"
 #include "wtf/Forward.h"
 #include "wtf/Functional.h"
 #include "wtf/OwnPtr.h"
@@ -53,6 +54,10 @@ enum WorkerThreadStartMode {
     PauseWorkerGlobalScopeOnStart
 };
 
+class WorkerThreadContext : public GarbageCollectedFinalized<WorkerThreadContext>, public LifecycleNotifier<WorkerThreadContext, WorkerThreadLifecycleObserver> {
+    USING_GARBAGE_COLLECTED_MIXIN(WorkerThreadContext);
+};
+
 // WorkerThread is a kind of WorkerBackingThread client. Each worker mechanism
 // can access the lower thread infrastructure via an implementation of this
 // abstract class. Multiple WorkerThreads can share one WorkerBackingThread.
@@ -123,6 +128,11 @@ public:
 
     ExitCode getExitCode();
 
+    WorkerThreadContext* workerThreadContext()
+    {
+        return m_workerThreadContext.get();
+    }
+
 protected:
     WorkerThread(PassRefPtr<WorkerLoaderProxy>, WorkerReportingProxy&);
 
@@ -196,6 +206,8 @@ private:
     // Scheduled when termination starts with TerminationMode::Force, and
     // cancelled when the worker thread is gracefully shut down.
     OwnPtr<ForceTerminationTask> m_scheduledForceTerminationTask;
+
+    Persistent<WorkerThreadContext> m_workerThreadContext;
 };
 
 } // namespace blink