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

content/browser/service_worker/service_worker_context_core.h

 // Copyright 2013 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_BROWSER_SERVICE_WORKER_SERVICE_WORKER_CONTEXT_CORE_H_
 #define CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_CONTEXT_CORE_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 178 matching lines @@
                                       ServiceWorkerProviderHost* provider_host);
   void UnregisterProviderHostByClientID(const std::string& client_uuid);
   ServiceWorkerProviderHost* GetProviderHostByClientID(
       const std::string& client_uuid);
 
   // A child process of |source_process_id| may be used to run the created
   // worker for initial installation.
   // Non-null |provider_host| must be given if this is called from a document.
   void RegisterServiceWorker(const GURL& pattern,
                              const GURL& script_url,
+                             bool use_cache,

[nhiroki, 2017/03/24 00:33:42]

Enum would be better than boolean for readability[1]. We could define it in
service_worker_types.h, for example, as follows:

  struct CONTENT_EXPORT ServiceWorkerRegistrationOptions {
    enum class UseCache { DontUse, Use };
    // ...
    UseCache use_cache;
  };

[1] "Consider changing the function signature to replace a bool argument with an
enum argument. This will make the argument values self-describing."
https://google.github.io/styleguide/cppguide.html#Implementation_Comments

[yuryu, 2017/03/28 05:08:56]

Done.

                              ServiceWorkerProviderHost* provider_host,
                              const RegistrationCallback& callback);
   void UnregisterServiceWorker(const GURL& pattern,
                                const UnregistrationCallback& callback);
 
   // Callback is called issued after all unregistrations occur.  The Status
   // is populated as SERVICE_WORKER_OK if all succeed, or SERVICE_WORKER_FAILED
   // if any did not succeed.
   void UnregisterServiceWorkers(const GURL& origin,
                                 const UnregistrationCallback& callback);
@@ skipping 169 matching lines @@
   scoped_refptr<base::ObserverListThreadSafe<ServiceWorkerContextObserver>>
       observer_list_;
   base::WeakPtrFactory<ServiceWorkerContextCore> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ServiceWorkerContextCore);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_CONTEXT_CORE_H_