Navigation API deferred commit

[noamr]

こんにちは TAG-さん!

I'm requesting a TAG review of "deferred commit" behavior for navigation API.

This is a small extension of the navigation API, which was previously reviewed in #605 and #717.

Explainer¹ (minimally containing user needs and example code): https://github.com/WICG/navigation-api/blob/main/README.md#deferred-commit
User research: Actively discussed on our issue tracker: WICG/navigation-api#277, also requested by major frameworks.
Security and Privacy self-review²: None - this shouldn't expose anything that isn't already available
GitHub repo (if you prefer feedback filed there): https://github.com/WICG/navigation-api/
Primary contacts (and their relationship to the specification):
Nate Chapin (@natechapin), Google
Noam Rosenthal (@noamr), Google
Domenic Denicola (@domenic), Google
Organization/project driving the design: Google
External status/issue trackers for this feature (publicly visible, e.g. Chrome Status): https://chromestatus.com/feature/5134734612496384.
Further details:
We recognize that this might be too small for TAG to review, but we'd let TAG be the judge of that.

I have reviewed the TAG's Web Platform Design Principles
The group where the incubation/design work on this is being done (or is intended to be done in the future): WICG
The group where standardization of this work is intended to be done ("unknown" if not known): WHATWG
Existing major pieces of multi-stakeholder review or discussion of this design: WICG/navigation-api#225
Major unresolved issues with or opposition to this design: None yet. The main point of debate has been the name. I am happy to consider alternatives to sourceElement.
This work is being funded by: Google
We'd prefer the TAG provide feedback as (please delete all but the desired option):
💬 leave review feedback as a comment in this issue and @-notify [@natechapin, @domenic, @noamr]