Why? To better support Save As or saving to Web archive.
Created attachment 112431 [details]
Perhaps it should ultimately be the job of PluginController implementation to save plug-in resources as necessary. But it's not clear to me how to structure that, and PDF is the only plug-in that currently needs this anyway.
Comment on attachment 112431 [details]
View in context: https://bugs.webkit.org/attachment.cgi?id=112431&action=review
r=me but I’d really like you to explicitly state why this should be done
> + Embedded PDFs should be known to DocumentLoader
This bug title doesn’t say why they should be known to DocumentLoader. And nothing in the change log says why either.
Bug description has the rationale.