Stub out ServiceWorkerRegistration and Version classes

content/browser/service_worker/service_worker_version.h

+// Copyright (c) 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_VERSION_H_
+#define CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_VERSION_H_
+
+#include "base/basictypes.h"
+#include "base/gtest_prod_util.h"
+#include "base/memory/ref_counted.h"
+#include "content/common/content_export.h"
+
+class GURL;
+
+namespace content {
+
+class ServiceWorkerRegistration;
+
+// This class corresponds to a specific version of a ServiceWorker
+// script for a given pattern. When a script is upgraded, there may be
+// more than one ServiceWorkerVersion "running" at a time, but only
+// one of them is active. This class connects the actual script with a
+// running worker. Instances of this class are in one of three states:
+// - Pending: The script is in the process of being installed. There
+//            may be another active script running.
+// - Active: The script is the only worker handling requests for the
+//           registration's pattern.
+// - Shutdown: This script version is no longer active and is likely
+//             in the process of cleaning itself up. This happens when
+//             a script is upgraded to a new ServiceWorkerVersion, or
+//             during unregistration.

[michaeln, 2013/11/14 00:27:33]

This is a helpful comment. I think there's some blurring of lines in the states
you listed, they're blurring the notion of running/notrunning vs the
"installstate".

I think these states you listed are orthogonal to running, I'd call them
"InstallStates". Shutdown is oddly named for that last install state. The method
as coded is more about unwinding the object graph than transitioning install
states.

InstallState install_state_;  // pending -> active -> obsolete(?)
RunState run_state_;   // stopped --> starting -> running -> stopping

bool is_shutdown_;   // implies nothing of install_state_ or run_state_, just
object teardown gunk

wdyt?

[alecflett, 2013/11/14 18:35:46]

Yeah this is a good breakdown. I'll clean up this comment. (But I won't add the
member variables just yet because compilers will complain if we declare and
don't use them.

+class CONTENT_EXPORT ServiceWorkerVersion
+    : NON_EXPORTED_BASE(public base::RefCounted<ServiceWorkerVersion>) {
+ public:
+  explicit ServiceWorkerVersion(
+      scoped_refptr<ServiceWorkerRegistration> registration);
+
+  void Shutdown();
+  bool is_shutdown() const { return is_shutdown_; }
+
+ private:
+  ~ServiceWorkerVersion();
+  friend class base::RefCounted<ServiceWorkerVersion>;
+
+  bool is_shutdown_;
+  scoped_refptr<ServiceWorkerRegistration> registration_;
+
+  DISALLOW_COPY_AND_ASSIGN(ServiceWorkerVersion);
+};
+}  // namespace content
+#endif  // CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_VERSION_H_