Expose SSLInfo::pkp_bypassed to devtools security panel.

This adds the necessary plumbing to expose in devtools when public-key pinning is bypassed (due to a local trust anchor), by way of SecurityStyleExplanations. The goal is to allow the security panel to display when pins are bypassed, in order to help developers debug pinning implementations.

BUG=566144

Review-Url: https://codereview.chromium.org/2066483009
Cr-Commit-Position: refs/heads/master@{#402586}
9 files changed