ServiceWorker: Change the return value of ServiceWorkerRegistration::unregister to boolean (3/4)

Source/modules/serviceworkers/ServiceWorkerRegistration.cpp

Index: Source/modules/serviceworkers/ServiceWorkerRegistration.cpp
diff --git a/Source/modules/serviceworkers/ServiceWorkerRegistration.cpp b/Source/modules/serviceworkers/ServiceWorkerRegistration.cpp
index 51fac02f7acc28b48a2512c29839871ad2f3f483..0c37820c17937d7b406036b0639fc6fe05d4247e 100644
--- a/Source/modules/serviceworkers/ServiceWorkerRegistration.cpp
+++ b/Source/modules/serviceworkers/ServiceWorkerRegistration.cpp
@@ -20,23 +20,6 @@
 
 namespace blink {
 
-class UndefinedValue {
-public:
-    typedef WebServiceWorkerRegistration WebType;
-    static V8UndefinedType take(ScriptPromiseResolver* resolver, WebType* registration)
-    {
-        ASSERT(!registration); // Anything passed here will be leaked.
-        return V8UndefinedType();
-    }
-    static void dispose(WebType* registration)
-    {
-        ASSERT(!registration); // Anything passed here will be leaked.
-    }
-
-private:
-    UndefinedValue();
-};
-
 class BooleanValue {
 public:
     typedef bool WebType;
@@ -130,11 +113,7 @@ ScriptPromise ServiceWorkerRegistration::unregister(ScriptState* scriptState)
         return promise;
     }
 
-#ifdef DISABLE_SERVICEWORKER_UNREGISTER_RESOLVE_TO_BOOLEAN
-    m_provider->unregisterServiceWorker(scopeURL, new CallbackPromiseAdapter<UndefinedValue, ServiceWorkerError>(resolver));
-#else
     m_provider->unregisterServiceWorker(scopeURL, new CallbackPromiseAdapter<BooleanValue, ServiceWorkerError>(resolver));
-#endif
     return promise;
 }