[webnfc] Change NDEF{Record,Message} to be IDL interface type

The corresponding spec changes were introduced in:
https://github.com/w3c/web-nfc/pull/240

BUG=520391

Change-Id: I50ff37d69ef1e79c32682493d3133f639226aac0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1684664
Commit-Queue: Leon Han <leon.han@intel.com>
Reviewed-by: Rijubrata Bhaumik <rijubrata.bhaumik@intel.com>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#679895}