(1) Chrome data compression proxy should use QUIC only if
it is part of data compression QUIC field trial.

(2) If QUIC is disabled by command line switch or flag,
then QUIC should be disabled globally, including usage of
QUIC in data compression proxy.

(3) If Chrome is part of data compression QUIC field trial,
it does NOT enable QUIC for non-proxy URLs.

BUG=343579

Review URL: https://codereview.chromium.org/903213003

Cr-Original-Commit-Position: refs/heads/master@{#317232}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: ed0aeccb2df07b46ca69d7328d9fab6d5aae5f8e
5 files changed