Add IsAlternativeServiceBroken(), remove is_broken.

Add HttpServerProperties::IsAlternativeServiceBroken(), remove
AlternateProtocolInfo.is_broken.  An alternative service can be broken by
itself, not with respect to an origin.

BUG=392576
R=rch@chromium.org

Review URL: https://codereview.chromium.org/995013004

Cr-Commit-Position: refs/heads/master@{#320116}
10 files changed