Split the desktop portion of application_lifetime.cc into its own file.

chrome/browser/lifetime/application_lifetime_internal.h

+// Copyright 2015 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_LIFETIME_APPLICATION_LIFETIME_INTERNAL_H_
+#define CHROME_BROWSER_LIFETIME_APPLICATION_LIFETIME_INTERNAL_H_
+
+#include "base/basictypes.h"
+
+// Various helper functions shared between application_lifetime* files.
+
+namespace chrome {
+
+namespace internal {
+
+void AttemptExitInternal(bool try_to_quit_application);
+
+#if !defined(OS_ANDROID) && !defined(OS_IOS)
+#if defined(OS_CHROMEOS)
+void NotifyAndTerminateInternalCrOS();
+#else
+void AttemptExitInternalDesktop();
+#endif
+#endif  // !defined(OS_ANDROID) && !defined(OS_IOS)
+
+}  // namespace internal
+
+}  // namespace chrome
+
+#endif  // CHROME_BROWSER_LIFETIME_APPLICATION_LIFETIME_INTERNAL_H_
+