GitLab

Don't allow calls to proceed once the associated content has been
destroyed.

Bug: 1121414
Test: example in the bug no longer crashes
Change-Id: I3bdeb86f2020f684958b624fcc30438babfb5004
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2378889Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Xiaohan Wang <xhwang@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: John Rummell <jrummell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#805561}