Add external extensions json source in proper mac location.

chrome/common/chrome_paths_internal.h

 // Copyright (c) 2011 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_COMMON_CHROME_PATHS_INTERNAL_H_
 #define CHROME_COMMON_CHROME_PATHS_INTERNAL_H_
 #pragma once
 
 #include "build/build_config.h"
 
@@ skipping 58 matching lines @@
 // Most of the application is further contained within the framework.  The
 // framework bundle is located within the versioned directory at a specific
 // path.  The only components in the versioned directory not included in the
 // framework are things that also depend on the framework, such as the helper
 // app bundle.
 FilePath GetFrameworkBundlePath();
 
 // Get the local library directory.
 bool GetLocalLibraryDirectory(FilePath* result);
 
+// Get the global Application Support directory (under /Library/).
+bool GetGlobalApplicationSupportDirectory(FilePath* result);
+
 // Returns the NSBundle for the outer browser application, even when running
 // inside the helper. In unbundled applications, such as tests, returns nil.
 NSBundle* OuterAppBundle();
 
 #endif  // OS_MACOSX
 
 }  // namespace chrome
 
 #endif  // CHROME_COMMON_CHROME_PATHS_INTERNAL_H_