Introduce ServiceWorkerHandle for tracking WebServiceWorkerImpl reference

content/browser/service_worker/service_worker_handle.cc

+// 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.
+
+#include "content/browser/service_worker/service_worker_context_core.h"
+#include "content/browser/service_worker/service_worker_handle.h"
+#include "content/browser/service_worker/service_worker_registration.h"
+
+namespace content {
+
+scoped_ptr<ServiceWorkerHandle> ServiceWorkerHandle::Create(
+    base::WeakPtr<ServiceWorkerContextCore> context,
+    IPC::Sender* sender,
+    ServiceWorkerVersion* version) {
+  if (!context || !version)
+    return scoped_ptr<ServiceWorkerHandle>();
+  ServiceWorkerRegistration* registration =
+      context->GetLiveRegistration(version->registration_id());
+  return make_scoped_ptr(
+      new ServiceWorkerHandle(context, sender, registration, version));
+}
+
+ServiceWorkerHandle::ServiceWorkerHandle(
+    base::WeakPtr<ServiceWorkerContextCore> context,
+    IPC::Sender* sender,
+    ServiceWorkerRegistration* registration,
+    ServiceWorkerVersion* version)
+    : context_(context),
+      sender_(sender),
+      registration_(registration),
+      version_(version) {
+  // context_->IncrementRegistrationCacheCount(registration);
+}
+
+ServiceWorkerHandle::~ServiceWorkerHandle() {
+  // We can discard the registration after all documents/handles that
+  // have a reference to the registration is closed or freed up, but
+  // could also keep it alive in cache for a while with some timer so that
+  // we don't need to re-create the same registration over and over?
+  //
+  // if (context_)
+  //   context_->DecrementRegistrationCacheCount(registration);
+}
+
+void ServiceWorkerHandle::OnVersionStateChanged() {
+  // TODO(kinuko): Implement.
+}
+
+}  // namespace content