Add BuildStats pipeline for PathKit binaries

This should be extensible to do something similar
for libskia and other outputs.

Bug: skia:
Change-Id: Id9f30a82f4eb0e7ce868a32409b1be429917e7f6
Reviewed-on: https://skia-review.googlesource.com/c/160220
Reviewed-by: Eric Boren <borenet@google.com>
14 files changed