[PartitionAlloc] Document apple lock options

Change-Id: I0716d08114bcbed8c9076e809204ea0557724313
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6158866
Commit-Queue: Benoit Lize <lizeb@chromium.org>
Reviewed-by: Takashi Sakamoto <tasak@google.com>
Cr-Commit-Position: refs/heads/main@{#1404056}
NOKEYCHECK=True
GitOrigin-RevId: f02982ba8b99e5b2f3acd32c69029278a034a0c7
1 file changed