Tweak scripts to fix CK builds with python 3

- print -> print()
- xrange() gone in 3, but range() works similarly - if somewhat
  less efficient in 2
- read() returns strings in python 2 vs. bytes in 3

Change-Id: Ia720551832ef75edbf9235b80a06e2ffa3ddf4b5
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/299444
Commit-Queue: Florin Malita <fmalita@google.com>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
2 files changed