Update selectors to 0.10, with ToCss serialization.
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r? @emilio
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10933/shorthands
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This implements the serialization of nearly all of the css shorthand properties with the following exceptions:
1. font - this may be implemented correctly, but I am not 100% sure
2. border-radius - I do not know how to implement this, since I am not familiar with how the property works
3. background - this is implemented, but I think that the implementation might be a tiny bit off.
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Fix restyling on viewport resize.
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Fixes https://github.com/servo/servo/issues/12835
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Support 'word-spacing' for geckolib
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Prefer length and percentage for word spacing
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The goal is to make use of `LengthOrPercentage` for word spacing in `ShapingOptions`, but since it makes use of `f32` which doesn't implement `Hash`, we're going for `NotNan<f32>` from [ordered-float](https://github.com/reem/rust-ordered-float/), which supports hashing. Instead of implementing `Hash` for `LengthOrPercentage` and thereby the inner types like `CSSFloat`, `CalcLengthOrPercentage`, etc., we convert it to `(Au, NotNan<f32>)`.
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style: Add support for parsing and serialization of <basic-shape>s
Still WIP: I still need to use this somewhere and make serialization minimal. I'm not sure if I should do either in this PR.
The only other browser that handles basic shapes doesn't serialize correctly either (https://bugzilla.mozilla.org/show_bug.cgi?id=1290864), so that's not something we need to get done now.
As far as using this somewhere, I have the following options:
- Merge this now, work on using it in stylo in a followup.
- Just write extensive unit tests for parsing/serialization for now (stylo in a followup)
- Use this for clip-path in stylo only (which I intend to do anyway, just not sure if I should do it in this PR)
- Use this for clip-path in Servo (I'd rather not do this; this would be a huge change requiring a lot more layout knowledge than I currently have)
Thoughts? Review? @SimonSapin @bholley
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Add support for background-position in geckolib.
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r? @Manishearth
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