gpu: Add ANGLE commit to program cache hash.

ANGLE rejects program binaries compiled from a different ANGLE,
because the program format can change, and other incompatibilities.
Add the commit id to the cache hash so the cache layer can skip
trying to compile these shaders.

This change should mostly affect developers who are testing Chrome
and modifying ANGLE between compiles.


Review URL:

Cr-Commit-Position: refs/heads/master@{#341713}
3 files changed