Add unique identifier to "PerformanceResourceTiming" API

[monica-ch]

Explainer doc for the feedback.

[noamr]

Thanks for working on this! I'm a bit confused about how the solution (specifically option 1) maps to the use case.
Seems like the use case is about mapping resource timing entries to fetch events, but the solution in option 1 only deals with navigations and maps the clientId, which would be the same across resources?

This OP alludes to that but this explainer doesn't...

Another issue with this is that mapping a response to a clientId only works if you don't use caches, which often beats the purpose of using a service-worker in the first place. A Cache allows you to reuse responses across clients, and this kind of mapping would break on the first response reuse.

[fabiorocha]

Looks like both files are almost identical. I assume we only need one of them?

[david-risney]

This <br> and the next <br> look weirdly out of place as the only embedded HTML in the document. Can you replace with an additional newline?

[victorhuangwq]

fixed

[david-risney]

All of the sample code in this document contains code something like this

      const entries = self.performance.getEntriesByType("resource"); 
      const timing = entries.find(e => e.responseId === response.responseId); 

Should we also be proposing a new Performance function to help find these entries?

partial interface Performance {
  PerformanceEntry getEntryById (DOMString id);
}

      const timing = self.performance.getEntryById(response.responseId); 

[victorhuangwq]

I think getEntryById might be confusing, at least for the current explainer - as there are quite a few different kinds of Ids mentioned. Will keep the current sample code for now.

[david-risney]

For option 2 I thought the request ID is optional and will be generated by the user agent if not provided? If so then 'Developers do not need to generate manage RequestIds' for option 2 is true - they don't need to. Maybe this row is supposed to be about removing flexibility for end devs to use their own IDs?

[victorhuangwq]

Addressed.

[fabiorocha]

LGTM after pending comments are addressed.

[victorhuangwq]

@david-risney I have mostly addressed the comments. Do take a look