Blink-layer update to match WebAuthN spec

1 of many CLs to merge WebAuthN with the Cred Man API. This change
renames idl components and updates the corresponding idl test.
(This changes as much as possible short of depending on anything in
credential manager).

BUG=664630

Review-Url: https://codereview.chromium.org/2966523002
Cr-Commit-Position: refs/heads/master@{#486648}
47 files changed