Apply HSTS to WebSocket connections.
With this change, ws: connections to hosts which have an existing HSTS
pin will be automatically changed to use wss:, ie. SSL.
In addition, Strict-Transport-Security headers that are sent from a wss:
server with a valid SSL certificate will be enforced on subsequent ws:
and http: connections to the same host.
This CL also modifies HttpNetworkTransaction to treat wss: the same as
https:.
BUG=455215, 446480
TEST=net_unittests
R=rsleevi@chromium.org, tyoshino@chromium.org
Review URL: https://codereview.chromium.org/
903553005
Cr-Commit-Position: refs/heads/master@{#317252}