AppShell support for Mac.

extensions/shell/app/shell_main.cc

 // Copyright 2014 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 "content/public/app/content_main.h"
 #include "extensions/shell/app/shell_main_delegate.h"
 
 #if defined(OS_WIN)
 #include "content/public/app/startup_helper_win.h"
 #include "sandbox/win/src/sandbox_types.h"
 #endif
 
-#if defined(OS_WIN)
+#if defined(OS_MACOSX)
+#include "extensions/shell/app/shell_main_mac.h"
+#endif
+
+#if defined(OS_MACOSX)
+int main(int argc, const char** argv) {
+  // Do the delegate work in shell_main_mac to avoid having to export the
+  // delegate types.
+  return ::ContentMain(argc, argv);
+}
+#elif defined(OS_WIN)
 int APIENTRY wWinMain(HINSTANCE instance, HINSTANCE, wchar_t*, int) {
-#else
-int main(int argc, const char** argv) {
-#endif
   extensions::ShellMainDelegate delegate;
   content::ContentMainParams params(&delegate);
 
-#if defined(OS_WIN)
   sandbox::SandboxInterfaceInfo sandbox_info = {0};
   content::InitializeSandboxInfo(&sandbox_info);
   params.instance = instance;
   params.sandbox_info = &sandbox_info;
-#else
-  params.argc = argc;
-  params.argv = argv;
-#endif
 
   return content::ContentMain(params);
 }
+#else  // non-Mac POSIX
+int main(int argc, const char** argv) {
+  extensions::ShellMainDelegate delegate;
+  content::ContentMainParams params(&delegate);
+
+  params.argc = argc;
+  params.argv = argv;
+
+  return content::ContentMain(params);
+}
+#endif