GitLab

Flash is going to be removed in M88, so mark related extension APIs as
deprecated and make them a no-op.

Bug: 1135788, 1135791
Change-Id: Idd2ceefcbe8eb6baeb31f44a4f3b12283253939b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2466236
Commit-Queue: Christian Dullweber <dullweber@chromium.org>
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Reviewed-by: David Bertoni <dbertoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#819321}