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/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::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->SetKeepsBrowserProcessAlive();
+      break;
+    }
+    default:
+      NOTREACHED();
+    }
+}
+
+}  // namespace extensions