First pass at content shell for the Mac. Doesn't work yet.

content/shell/shell_content_main.h

+// 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 CONTENT_SHELL_SHELL_CONTENT_MAIN_H_
+#define CONTENT_SHELL_SHELL_CONTENT_MAIN_H_
+#pragma once
+
+#include "base/basictypes.h"
+
+#if defined(OS_MACOSX)
+extern "C" {
+__attribute__((visibility("default")))
+int ContentMain(int argc,
+                const char** argv);
+}  // extern "C"
+#endif  // OS_MACOSX
+
+#endif  // CONTENT_SHELL_SHELL_CONTENT_MAIN_H_