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

third_party/WebKit/Source/modules/serviceworkers/ServiceWorkerGlobalScope.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 202 matching lines @@
   visitor->Trace(clients_);
   visitor->Trace(registration_);
   WorkerGlobalScope::Trace(visitor);
 }
 
 void ServiceWorkerGlobalScope::importScripts(const Vector<String>& urls,
                                              ExceptionState& exception_state) {
   // Bust the MemoryCache to ensure script requests reach the browser-side
   // and get added to and retrieved from the ServiceWorker's script cache.
   // FIXME: Revisit in light of the solution to crbug/388375.
+  // TODO(yuryu): Update the method to respect cache policy.
   for (Vector<String>::const_iterator it = urls.begin(); it != urls.end(); ++it)
     GetExecutionContext()->RemoveURLFromMemoryCache(CompleteURL(*it));
   WorkerGlobalScope::importScripts(urls, exception_state);
 }
 
 CachedMetadataHandler*
 ServiceWorkerGlobalScope::CreateWorkerScriptCachedMetadataHandler(
     const KURL& script_url,
     const Vector<char>* meta_data) {
   return ServiceWorkerScriptCachedMetadataHandler::Create(this, script_url,
                                                           meta_data);
 }
 
 void ServiceWorkerGlobalScope::ExceptionThrown(ErrorEvent* event) {
   WorkerGlobalScope::ExceptionThrown(event);
   if (WorkerThreadDebugger* debugger =
           WorkerThreadDebugger::From(GetThread()->GetIsolate()))
     debugger->ExceptionThrown(GetThread(), event);
 }
 
 }  // namespace blink