Add 'b' as a BUG= identifier for buganizer.

Buganizer is opening up for external projects too. Allow to use BUG=b:9999 to
refer to a buganizer ticket.

BUG=None
TEST=use new syntax in a CL and re-upload it

Change-Id: I733a8907fea9beb0252214338f2db16503c5b07a
Reviewed-on: https://chromium-review.googlesource.com/257831
Commit-Queue: Stefan Sauer <ensonic@google.com>
Tested-by: Stefan Sauer <ensonic@google.com>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
2 files changed