Revert of Service Worker: Make ServiceWorkerRegistration.update() return a promise. (Blink 1/3)

public/platform/WebServiceWorkerRegistration.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef WebServiceWorkerRegistration_h
 #define WebServiceWorkerRegistration_h
 
 #include "public/platform/WebCallbacks.h"
 #include "public/platform/WebURL.h"
 
 namespace blink {
 
 class WebServiceWorkerProvider;
 class WebServiceWorkerRegistrationProxy;
 struct WebServiceWorkerError;
 
 class WebServiceWorkerRegistration {
 public:
     virtual ~WebServiceWorkerRegistration() { }
 
-    using WebServiceWorkerUpdateCallbacks = WebCallbacks<void, WebServiceWorkerError*>;
     using WebServiceWorkerUnregistrationCallbacks = WebCallbacks<bool*, WebServiceWorkerError*>;
 
     virtual void setProxy(WebServiceWorkerRegistrationProxy*) { }
     virtual WebServiceWorkerRegistrationProxy* proxy() { return nullptr; }
     virtual void proxyStopped() { }
 
     virtual WebURL scope() const { return WebURL(); }
-    // TODO(jungkees):
-    // void update(p) remains temporarily before the chromium-side companion
-    // patch lands: https://codereview.chromium.org/1270513002/.
-    // Before the chromium-side patch lands, the new update(p, c) will
-    // internally call this->update(p) to work with the existing code base.
-    // The final changes will be incorporated with the Blink layout patches.
     virtual void update(WebServiceWorkerProvider*) { }
-    virtual void update(WebServiceWorkerProvider* provider, WebServiceWorkerUpdateCallbacks*) { this->update(provider); }
     virtual void unregister(WebServiceWorkerProvider*, WebServiceWorkerUnregistrationCallbacks*) { }
 };
 
 } // namespace blink
 
 #endif // WebServiceWorkerRegistration_h