[Infra] Add ability to specify a cc_list to git_utils.py

Bug: skia:7310
Change-Id: I8ef505025e2cf0b7859e54e85293efed16704398
Reviewed-on: https://skia-review.googlesource.com/82200
Commit-Queue: Ravi Mistry <rmistry@google.com>
Reviewed-by: Eric Boren <borenet@google.com>
1 file changed