Implement updateViaCache flag and no-cache by default for main service worker scripts

content/child/service_worker/web_service_worker_registration_impl.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 CONTENT_CHILD_SERVICE_WORKER_WEB_SERVICE_WORKER_REGISTRATION_IMPL_H_
 #define CONTENT_CHILD_SERVICE_WORKER_WEB_SERVICE_WORKER_REGISTRATION_IMPL_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 31 matching lines @@
   void SetInstalling(const scoped_refptr<WebServiceWorkerImpl>& service_worker);
   void SetWaiting(const scoped_refptr<WebServiceWorkerImpl>& service_worker);
   void SetActive(const scoped_refptr<WebServiceWorkerImpl>& service_worker);
 
   void OnUpdateFound();
 
   // blink::WebServiceWorkerRegistration overrides.
   void setProxy(blink::WebServiceWorkerRegistrationProxy* proxy) override;
   blink::WebServiceWorkerRegistrationProxy* proxy() override;
   blink::WebURL scope() const override;
+  bool useCache() const override;
   void update(
       blink::WebServiceWorkerProvider* provider,
       std::unique_ptr<WebServiceWorkerUpdateCallbacks> callbacks) override;
   void unregister(blink::WebServiceWorkerProvider* provider,
                   std::unique_ptr<WebServiceWorkerUnregistrationCallbacks>
                       callbacks) override;
   void enableNavigationPreload(
       bool enable,
       blink::WebServiceWorkerProvider* provider,
       std::unique_ptr<WebEnableNavigationPreloadCallbacks> callbacks) override;
@@ skipping 42 matching lines @@
   blink::WebServiceWorkerRegistrationProxy* proxy_;
 
   std::vector<QueuedTask> queued_tasks_;
 
   DISALLOW_COPY_AND_ASSIGN(WebServiceWorkerRegistrationImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_CHILD_SERVICE_WORKER_WEB_SERVICE_WORKER_REGISTRATION_IMPL_H_