AFDO: Consider differences in builds while determining staleness

Branches other than master can have AFDO data generated a long time
ago but only with little changes. We consider this OK.

BUG=none
TEST=none

Change-Id: I89c9f9b7ff8a2b4cd8a4d77fdebba06061acfd67
Reviewed-on: https://chromium-review.googlesource.com/388915
Commit-Ready: Ting-Yuan Huang <laszio@chromium.org>
Tested-by: Ting-Yuan Huang <laszio@chromium.org>
Reviewed-by: Luis Lozano <llozano@chromium.org>
1 file changed