GitLab

Setting the same key twice is allowed but a different key is still
something that should never happen.

This permits service such as network process to run in-process
and also fixes --single-process mode.

BUG=1000799,1016384

Change-Id: I9da8221adc763d1188b64589dafedeee866d585f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1872155Reviewed-by: Christos Froussios <cfroussios@chromium.org>
Commit-Queue: Will Harris <wfh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#707865}