Fix scan sources.
Fix scan sources.

I added files in a directory called "utility" which confuses this script
when it sees
#include <utility>
Since it gets confused between this file and the directory. This adds a check
if the file is a directory.

TEST=none
BUG=none
Review URL: http://codereview.chromium.org/9085024

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@7513 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

sbc100/native_client,nacl-webkit/native_client,nacl-webkit/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client,sbc100/native_client,nacl-webkit/native_client,sbc100/native_client,nacl-webkit/native_client,nacl-webkit/native_client