Add in-profile external_extensions.json file for Chrome OS OEM customization.

chrome/common/chrome_paths.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_H__
 #define CHROME_COMMON_CHROME_PATHS_H__
 #pragma once
 
 #include "build/build_config.h"
 
@@ skipping 31 matching lines @@
 #if !defined(OS_MACOSX) && defined(OS_POSIX)
   DIR_POLICY_FILES,             // Directory for system-wide read-only
                                 // policy files that allow sys-admins
                                 // to set policies for chrome. This directory
                                 // contains subdirectories.
 #endif
 #if defined(OS_MACOSX)
   DIR_MANAGED_PREFS,            // Directory that stores the managed prefs plist
                                 // files for the current user.
 #endif
+#if defined(OS_CHROMEOS)
+  DIR_USER_EXTERNAL_EXTENSIONS,  // Directory for per-user external extensions.
+                                 // Used for OEM customization on Chrome OS.
+                                 // Getting this path does not create it.
+#endif
+
   FILE_RESOURCE_MODULE,         // Full path and filename of the module that
                                 // contains embedded resources (version,
                                 // strings, images, etc.).
   FILE_LOCAL_STATE,             // Path and filename to the file in which
                                 // machine/installation-specific state is saved.
   FILE_RECORDED_SCRIPT,         // Full path to the script.log file that
                                 // contains recorded browser events for
                                 // playback.
   FILE_GEARS_PLUGIN,            // Full path to the gears.dll plugin file.
   FILE_FLASH_PLUGIN,            // Full path to the internal Flash plugin file.
@@ skipping 18 matching lines @@
 
   PATH_END
 };
 
 // Call once to register the provider for the path keys defined above.
 void RegisterPathProvider();
 
 }  // namespace chrome
 
 #endif  // CHROME_COMMON_CHROME_PATHS_H__