I currently have a patch up (for bug 1376587) which exposes much more security information in ProgressListener.onSecurityChange() in a GeckoBundle (keys/values documented in GeckoView.java). This GeckoBundle is compatible with SiteIdentity.update(), so it should be easy enough to build a SiteIdentity in CustomTabsActivity and restore some of the old ActionBarPresenter code.
Created attachment 8895845 [details] [diff] [review] Expose security certificate information in custom tabs This adds a class, CustomTabsSecurityPopup, a bit similar to SiteIdentityPopup used by Fennec, to display security cert information when a user taps on the security icon in a custom tab.
Pushed by email@example.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/50e74b401083 Expose security information in custom tabs. r=snorp