Keep browser process alive while there are platform apps with background pages running.

chrome/browser/extensions/platform_app_service.cc

+// 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.
+
+#include "chrome/browser/extensions/platform_app_service.h"
+
+#include "chrome/browser/extensions/extension_host.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/profiles/profile_dependency_manager.h"
+#include "chrome/common/chrome_notification_types.h"
+#include "chrome/common/extensions/extension.h"
+#include "content/public/browser/browser_context.h"
+#include "content/public/browser/notification_details.h"
+#include "content/public/browser/notification_service.h"
+#include "content/public/browser/notification_types.h"
+
+namespace extensions {
+
+PlatformAppService::PlatformAppService(Profile* profile) {
+  registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_HOST_CREATED,
+                 content::Source<content::BrowserContext>(profile));
+}
+
+PlatformAppService::~PlatformAppService() {}
+
+void PlatformAppService::CreateInstance(Profile* profile) {
+  Factory::GetForProfile(profile);
+}
+
+void PlatformAppService::Observe(int type,
+                                  const content::NotificationSource& source,
+                                  const content::NotificationDetails& details) {
+  switch (type) {
+    case chrome::NOTIFICATION_EXTENSION_HOST_CREATED: {
+      ExtensionHost* host = content::Details<ExtensionHost>(details).ptr();
+      if (host->extension()->is_platform_app())
+        host->KeepBrowserProcessAlive();
+      break;
+    }
+    default:
+      NOTREACHED();
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////

[Aaron Boodman, 2012/10/31 07:31:22]

It seems like there could be a factory template or something instead of
everybody recoding this boilerplate, but oh well.

[benwells, 2012/10/31 08:08:22]

Yes, it could be a template with traits and suchlike.

+// Factory boilerplate
+
+// static
+PlatformAppService* PlatformAppService::Factory::GetForProfile(
+    Profile* profile) {
+  return static_cast<PlatformAppService*>(
+      GetInstance()->GetServiceForProfile(profile, true));
+}
+
+PlatformAppService::Factory* PlatformAppService::Factory::GetInstance() {
+  return Singleton<PlatformAppService::Factory>::get();
+}
+
+PlatformAppService::Factory::Factory()
+    : ProfileKeyedServiceFactory("PlatformAppService",
+                                 ProfileDependencyManager::GetInstance()) {
+}
+
+PlatformAppService::Factory::~Factory() {
+}
+
+ProfileKeyedService* PlatformAppService::Factory::BuildServiceInstanceFor(
+    Profile* profile) const {
+  return new PlatformAppService(profile);
+}
+
+bool PlatformAppService::Factory::ServiceHasOwnInstanceInIncognito() const {
+  return true;
+}
+
+bool PlatformAppService::Factory::ServiceIsCreatedWithProfile() const {
+  return true;
+}
+
+bool PlatformAppService::Factory::ServiceIsNULLWhileTesting() const {
+  return false;
+}
+
+}  // namespace extensions