Lazy initialization for ProcessesEventRouter.

chrome/browser/extensions/api/processes/processes_api_service.h

+// Copyright (c) 2012 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 CHROME_BROWSER_EXTENSIONS_API_PROCESSES_PROCESSES_API_SERVICE_H__
+#define CHROME_BROWSER_EXTENSIONS_API_PROCESSES_PROCESSES_API_SERVICE_H__
+
+#include <string>
+
+#include "base/memory/scoped_ptr.h"
+#include "chrome/browser/extensions/event_router.h"
+#include "chrome/browser/profiles/profile_keyed_service.h"
+
+class Profile;
+
+namespace extensions {

[Aaron Boodman, 2012/11/07 04:08:20]

Nit: In the end, I don't think we want these in the extensions namespace (that
should just be the core). Not sure about this intermediate state tho.

[Yoyo Zhou, 2012/11/07 22:53:36]

Should they be in a namespace like processes_api? extensions_api_processes?
Whatever it is, I'd want to do it in another CL.

[Aaron Boodman, 2012/11/07 23:51:28]

I think it depends on whether they end up being their own module or not. It
seems like the pattern in Chrome is that all the modules except the top-level
code have namespaces.

So if they're just dumped into chrome/browser/extension_apis or something, then
no, they'd have no namespace. I sorta think this is the way it should be, just
because I can't think of any reason for extension API impls for Chrome to be
compilable separately from Chrome.

+class ProcessesEventRouter;
+
+// The profile-keyed service that manages the processes extension API.
+class ProcessesAPIService : public ProfileKeyedService,
+                            public EventRouter::Observer {
+ public:
+  explicit ProcessesAPIService(Profile* profile);
+  virtual ~ProcessesAPIService();
+
+  // Convenience method to get the ProcessesAPIService for a profile.
+  static ProcessesAPIService* Get(Profile* profile);
+
+  ProcessesEventRouter* processes_event_router() {
+    return processes_event_router_.get();
+  }
+
+  // EventRouter::Observer implementation.
+  virtual void OnListenerAdded(const std::string& event_name) OVERRIDE;
+  virtual void OnListenerRemoved(const std::string& event_name) OVERRIDE;
+
+ private:
+  Profile* profile_;
+
+  // Lazily initialized in OnListenerAdded.
+  scoped_ptr<extensions::ProcessesEventRouter> processes_event_router_;
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_API_PROCESSES_PROCESSES_API_SERVICE_H__