Add optional check for "Signed-off-by:" tag

Certain projects (such as Coreboot) require a sign-off. Add a check for
the sign-off field which can be enabled per-project.

TEST=Enabled sign-off by check on Coreboot project. Verified that commit
without sign-off was caught by presubmit. Verified that adding sign-off
allowed presubmit pass.

Change-Id: I6872cbbf66ae94afa1952baf8deedea9a1109f28
Original-Change-Id: I30e8b8ccc37413c3ea5942e8c4e3e628017b0b63
Reviewed-by: Shawn Nematbakhsh <>
Commit-Queue: Shawn Nematbakhsh <>
Tested-by: Shawn Nematbakhsh <>
Reviewed-by: Aaron Durbin <>
1 file changed