Make WebIDL callbacks permanently rooted
This replicates the same model that Promise uses right now, because it requires less thinking than coming up with something else.
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix#14447
- [ ] There are tests for these changes
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It could be used to have mutable JSVal fields without GC barriers.
With the removal of that trait, MutHeap and MutNullableHeap can respectively
be replaced by MutJS and MutNullableJS.
* `LonghandId` and `ShorthandId` are C-like enums
* `Atom` is used for the name of custom properties.
* `PropertyDeclarationId` is the identifier for `PropertyDeclaration`,
after parsing and shorthand expansion. (Longhand or custom property.)
* `PropertyId` represents any CSS property, e.g. in CSSOM.
(Longhand, shorthand, or custom.)
Using these instead of strings avoids some memory allocations and copies.
Urlmageddon
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Still needs a bunch of code in net to be converted in order to get more
advantage of this for images and stuff, but meanwhile this should help quite a
bit with #13778.
Still wanted to get this in.
r? @SimonSapin
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11485 make dom methods taking mut js content unsafe
This is a rebased version of PR #11595
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- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix#11485
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