Fix compile error in iossim.
A recent clang roll started causing the following warning:
../../../testing/iossim/iossim.mm:215:62: error: expression which evaluates to zero treated as a null pointer constant of type 'BOOL *' (aka 'signed char *') [-Werror,-Wnon-literal-null-conversion].
Just dropping the isDirectory parameter fixes the issue.
BUG=None
Review URL: https://chromiumcodereview.appspot.com/
10832399
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@152425 0039d316-1c4b-4281-b951-d872f2087c98