GitLab

Adds toplevel.flow trace events for message pipe closure to link the
closure of one endpoint to the detection of that closure by its peer
endpoint. This allows pipe closures to be followed like other IPC
message events, since pipe closure is often an important type of IPC
in itself.

Bug: None
Change-Id: I78c928972eddebef26c1ea9765dd697c17807f63
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1733786
Commit-Queue: Ken Rockot <rockot@google.com>
Reviewed-by: Daniel Murphy <dmurph@chromium.org>
Cr-Commit-Position: refs/heads/master@{#683723}