GitLab

We now wait for the FastPathReady message before returning the result
for the StartReceivingMessages mojo call.

Fixed: 1134212
Change-Id: Ic1b64421544a90a7ae82b0d11f69edf64c2d1021
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2506391Reviewed-by: Alex Gough <ajgo@chromium.org>
Reviewed-by: Ryan Hansberry <hansberry@chromium.org>
Commit-Queue: James Vecore <vecore@google.com>
Cr-Commit-Position: refs/heads/master@{#822061}