In the process, merge the old canary function back in.
Bug: 132
Change-Id: Ib455320ecea67c839d0b4ac3882669d24f832b74
Reviewed-on: https://boringssl-review.googlesource.com/17765
Reviewed-by: Steven Valdez <svaldez@google.com>
Commit-Queue: David Benjamin <davidben@google.com>