Make ActiveScriptWrappable the GC mixin it is.

third_party/WebKit/Source/modules/serviceworkers/ServiceWorker.h

Index: third_party/WebKit/Source/modules/serviceworkers/ServiceWorker.h
diff --git a/third_party/WebKit/Source/modules/serviceworkers/ServiceWorker.h b/third_party/WebKit/Source/modules/serviceworkers/ServiceWorker.h
index 7ceddc3519972e88b147e0b5aa3cfa6042ad804e..1d93fa0764669d6044e25e5f125d176a48708dea 100644
--- a/third_party/WebKit/Source/modules/serviceworkers/ServiceWorker.h
+++ b/third_party/WebKit/Source/modules/serviceworkers/ServiceWorker.h
@@ -48,17 +48,16 @@ class ScriptPromiseResolver;
 
 class MODULES_EXPORT ServiceWorker final : public AbstractWorker, public ActiveScriptWrappable, public WebServiceWorkerProxy {
     DEFINE_WRAPPERTYPEINFO();
+    USING_GARBAGE_COLLECTED_MIXIN(ServiceWorker);
 public:
     static ServiceWorker* from(ExecutionContext*, PassOwnPtr<WebServiceWorker::Handle>);
 
     ~ServiceWorker() override;
+    DECLARE_VIRTUAL_TRACE();
 
     // Eager finalization needed to promptly release owned WebServiceWorker.
     EAGERLY_FINALIZE();
 
-    // Override 'operator new' to enforce allocation of eagerly finalized object.
-    DECLARE_EAGER_FINALIZATION_OPERATOR_NEW();
-
     void postMessage(ExecutionContext*, PassRefPtr<SerializedScriptValue> message, const MessagePortArray&, ExceptionState&);
 
     String scriptURL() const;