GitLab

Avoids a UAF by disconnecting the mojo::Receiver and mojo::Remote from
the pre-finalizer.

Bug: 1016574
Change-Id: Icdbba0e7798a93318df9931b4f1fe9004b6b8501
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1952085Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Darin Fisher <darin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#722542}