[Cronet] Fix false positive CHECK() failure with socket tagging and a proxy

Cronet was hitting CHECK() crashes when proxying HTTPS traffic through
HTTP proxies when a socket tag was applied.  There was no reason to
crash in these cases, so I'm fixing the CHECK() condition.

Bug: 920592
Change-Id: I0c5abd996d99e495c84aba3843286b96ddba624e
Reviewed-on: https://chromium-review.googlesource.com/c/1407430
Reviewed-by: Matt Menke <mmenke@chromium.org>
Commit-Queue: Paul Jensen <pauljensen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622548}
2 files changed