[worklets] Make WorkerThread handle both Worker and Worklet global scopes.

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

Index: third_party/WebKit/Source/core/workers/WorkerGlobalScope.h
diff --git a/third_party/WebKit/Source/core/workers/WorkerGlobalScope.h b/third_party/WebKit/Source/core/workers/WorkerGlobalScope.h
index 4e64e97bc445939dcffb9270ffaa8bfca8dd6fca..f1da743544013532875848595f3dbd70032a2d3b 100644
--- a/third_party/WebKit/Source/core/workers/WorkerGlobalScope.h
+++ b/third_party/WebKit/Source/core/workers/WorkerGlobalScope.h
@@ -74,7 +74,7 @@ public:
     virtual CachedMetadataHandler* createWorkerScriptCachedMetadataHandler(const KURL& scriptURL, const Vector<char>* metaData) { return nullptr; }
 
     KURL completeURL(const String&) const;
-    void dispose();
+    void dispose() final;
     void exceptionUnhandled(const String& errorMessage, std::unique_ptr<SourceLocation>);
 
     void registerEventListener(V8AbstractEventListener*);
@@ -123,7 +123,7 @@ public:
     // method). If this returns true, the worker is going to be shutdown after
     // the current task execution. Workers that don't support close operation
     // should always return false.
-    bool isClosing() const { return m_closing; }
+    bool isClosing() const final { return m_closing; }
 
     const KURL& url() const { return m_url; }
     WorkerThread* thread() const { return m_thread; }