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

chrome/browser/extensions/app_extension_host_delegate.h

Index: chrome/browser/extensions/app_extension_host_delegate.h
diff --git a/chrome/browser/extensions/app_extension_host_delegate.h b/chrome/browser/extensions/app_extension_host_delegate.h
new file mode 100644
index 0000000000000000000000000000000000000000..5eef9e0e0a4cee5649dd22b9229c4e52d92426c3
--- /dev/null
+++ b/chrome/browser/extensions/app_extension_host_delegate.h
@@ -0,0 +1,22 @@
+// 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_APP_EXTENSION_HOST_DELEGATE_H_
+#define CHROME_BROWSER_EXTENSIONS_APP_EXTENSION_HOST_DELEGATE_H_
+
+#include "chrome/browser/extensions/extension_host.h"
+
+namespace extensions {
+
+class AppBackgroundHostDelegate : public ExtensionHost::Delegate {
+ public:
+  AppBackgroundHostDelegate() {}
+  virtual ~AppBackgroundHostDelegate() {}
+
+  virtual bool KeepsBrowserProcessAlive() OVERRIDE;
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_APP_EXTENSION_HOST_DELEGATE_H_