GitLab

The MachPortRelay and MachPortBroker were not set up in all the
circumstances in which they were required.

This also changes the base::MachPortBroker to log more descriptive
failure messages.

Change-Id: Id711b7a30acb31c2c3366d31f4d0b0bfb1a2815d
Reviewed-on: https://chromium-review.googlesource.com/c/1371932Reviewed-by: Ken Rockot <rockot@google.com>
Reviewed-by: Mark Mentovai <mark@chromium.org>
Commit-Queue: Robert Sesek <rsesek@chromium.org>
Cr-Commit-Position: refs/heads/master@{#615634}