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

content/shell/shell_content_main.h

Index: content/shell/shell_content_main.h
diff --git a/content/shell/shell_content_main.h b/content/shell/shell_content_main.h
new file mode 100644
index 0000000000000000000000000000000000000000..d6ae276ca03e817bfb63da59fc5e3680eb2264e8
--- /dev/null
+++ b/content/shell/shell_content_main.h
@@ -0,0 +1,19 @@
+// 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_