Add NetworkIsolationKey to SpdySessionKey.

This will allow us to experiment with separating out connections by the
key, which has privacy benefits, but also performance costs. The key
has already been added to the socket pools themselves, but
SpdySessionKey bypasses socket pool GroupIds.

Bug: 963480
Change-Id: I54b75c2a299561c7d40ad790c23a33c191062a81
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1627243
Commit-Queue: Matt Menke <mmenke@chromium.org>
Reviewed-by: Ryan Hamilton <rch@chromium.org>
Cr-Commit-Position: refs/heads/master@{#663258}
15 files changed