Fix ridiculous DOM proxy getter performance
This implements the missing shadowing checks that were causing us to take many slow paths when dealing with proxy objects. Verified by running `tests/html/binding_perf.html` before and after and observing a 12x improvement.
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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix#12357
- [X] These changes do not require tests because we can't test performance yet.
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Use new name convention for Servo binding functions.
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This is the Servo part of [bug 1296173](https://bugzilla.mozilla.org/show_bug.cgi?id=1296173).
r? @bholley
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- [ ] These changes fix #__ (github issue number if applicable).
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- [ ] There are tests for these changes OR
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Support multiple backgrounds in both servo and stylo
(Commits do not build individually, but split up for review)
These patches make all of the background- properties accept multiple values, and add the layout code to display them.
Still needs some cleanup, and some testing, but it seems to work.
r? @SimonSapin
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Make GeckoDeclarationBlock refcounted
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This makes GeckoDeclarationBlock refcounted, so that it can share most of the logic Gecko currently uses for its existing `css::Declaration`. Although this is almost only useful for Gecko side, doing this in Servo side eliminates additional object allocation for holding it in the Gecko side.
Its Gecko side code change is in [bug 1296186](https://bugzilla.mozilla.org/show_bug.cgi?id=1296186). We may not want to land this before that part also gets reviewed.
r? @Manishearth
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Merge normal and important declarations in style rules
Have a single Vec instead of two. Fix#3426
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Include ServoBindingList.h for binding generating
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See [bug 1296594](https://bugzilla.mozilla.org/show_bug.cgi?id=1296594)
r? @bholley
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This is bug 1296594 on Gecko side.
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Update selectors to 0.10, with ToCss serialization.
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r? @emilio
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