GitLab

The Fuchsia FileDescriptorWatcher attempted to cancel the wait operation
on deletion, failing if the pump was already deleted because the
underlying wait port was no longer valid.

FileDescriptorWatcher now access the wait port handle via a WeakPtr to
the associated MessagePumpFuchsia, allowing it to skip cancelling the
operation in this case.

Bug: 738275
Change-Id: Icd2a8811219de182c9c9a3208224e46a9ce1d186
Reviewed-on: https://chromium-review.googlesource.com/575291
Commit-Queue: Wez <wez@chromium.org>
Reviewed-by: Kevin Marshall <kmarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#487314}