Provide a way to get the NDEFMessage and NDEFRecord size before writing

[Snapstromegon]

I did not find something like this in the spec or in Chrome's current canary (86.0.4196.0) implementation.

Problem Abstract

I'm trying to write some data to NFC Tags, but I want to know how large the NDEFMessage/Record is before I'm writing it (to predict fail/success cases).

Usecase

My usecase during origin trial was, that I write some optional history data into the record and I know exactly how large the size of my card is and I want to include as much of the history as possible.

Problem / Existing Workarounds

Currently I'd need to start at some point and do a lot of trial and error which results in many read/writes or I implement the calculation myself which might result in errors.

Proposed solution

Adding a "size" attribute (or something similar) to NDEFMessage and NDEFRecord would make this usecase way easier.