Add histogram to track NPN/ALPN.
Add histogram to track
* which TLS extension (NPN or ALPN) is used for protocol negotiation,
* in case of NPN, is there overlap or do we fall back,
* which protocol is selected.
This CL is draft, I still do not know how to call set_protocol_negotiation() in
NSS. I would love to do that in
SSLClientSocketNSS::Core::HandshakeSucceeded(), but that might not be the on
the same thread.
Review URL: https://codereview.chromium.org/
590513002
Cr-Commit-Position: refs/heads/master@{#299303}