We can drop async messages that contain CPOWs, which can cause us to
leak them either until we successfully send a CPOW or forever,
depending on the direction of the message. This is causing
intermittent leaks until shutdown with e10s-multi.
MozReview-Commit-ID: 3iIaIBZKZR2
--HG--
extra : rebase_source : 3383191e12fd4a4054ad8f9bdc3755e78c16caf1
The bulk of this commit was generated by running:
run-clang-tidy.py \
-checks='-*,llvm-namespace-comment' \
-header-filter=^/.../mozilla-central/.* \
-fix
