Update rewrite_includes.py for python3

Change-Id: Ib1b6f8c17554f8121bd2351b5b214e1b2a79f758
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/439776
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
1 file changed