GitLab

Only support it when socket pools are also split by the
NIK, because the key is grabbed from the session key and
will be empty when socket pools are not partitioned.

Bug: 1021617
Change-Id: Ib0f601b8b20deb2c4bb85ddb4e212eb71380d086
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1900556Reviewed-by: Zhongyi Shi <zhongyi@chromium.org>
Commit-Queue: Yao Xiao <yaoxia@chromium.org>
Cr-Commit-Position: refs/heads/master@{#719321}