Move Mac LaunchOnStartup enable/disable to File thread

chrome/browser/background_mode_manager_chromeos.cc

Index: chrome/browser/background_mode_manager_chromeos.cc
diff --git a/chrome/browser/background_mode_manager_chromeos.cc b/chrome/browser/background_mode_manager_chromeos.cc
new file mode 100644
index 0000000000000000000000000000000000000000..8439f187da475b3235cec648d1ccd68d4b64f395
--- /dev/null
+++ b/chrome/browser/background_mode_manager_chromeos.cc
@@ -0,0 +1,16 @@
+// Copyright (c) 2010 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/background_mode_manager.h"
+
+#include "app/l10n_util.h"
+#include "grit/generated_resources.h"
+
+void BackgroundModeManager::EnableLaunchOnStartup(bool should_launch) {
+  NOTREACHED();
+}
+
+string16 BackgroundModeManager::GetPreferencesMenuLabel() {
+  return l10n_util::GetStringUTF16(IDS_SETTINGS);
+}