Make sure only the right processes can access the profile path.

base/path_service.h

Index: base/path_service.h
diff --git a/base/path_service.h b/base/path_service.h
index 4b297385dfb8494ed9c4c68f43f9b8fd3596d3c2..6edc4fd7dd9c7943f2ab3d7535aa94d0ef8a4234 100644
--- a/base/path_service.h
+++ b/base/path_service.h
@@ -40,6 +40,19 @@ class BASE_EXPORT PathService {
   // over the lifetime of the app, so this method should be used with caution.
   static bool Override(int key, const FilePath& path);
 
+  // Overrides the path to a special directory or file.  This cannot be used to
+  // change the value of DIR_CURRENT, but that should be obvious.  Also, if the
+  // path specifies a directory that does not exist, the directory will be
+  // created if the |create| flag is set to true.  This method returns true if
+  // successful.
+  //
+  // If the given path is relative, then it will be resolved against
+  // DIR_CURRENT.
+  //
+  // WARNING: Consumers of PathService::Get may expect paths to be constant
+  // over the lifetime of the app, so this method should be used with caution.
+  static bool Override(int key, const FilePath& path, bool create);
+
   // To extend the set of supported keys, you can register a path provider,
   // which is just a function mirroring PathService::Get.  The ProviderFunc
   // returns false if it cannot provide a non-empty path for the given key.