... to ec358ccfd63a2a657c147329c7793d217e278a58.

This adds support for CBOR <-> Value.

v8 changes:
- Add StringUTF8Adapter (from Pavel's change)
- Add Binary::fromSpan (needed for the cbor->BinaryValue conversion).

Change-Id: I09746dc361df0b150b23697a20b287613558c003
Reviewed-on: https://chromium-review.googlesource.com/c/1470955
Commit-Queue: Pavel Feldman <pfeldman@chromium.org>
Reviewed-by: Pavel Feldman <pfeldman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59583}