stylo: Stop restyling display: none elements, remove the has_changed hack that made us use ReconstructFrame unconditionally.
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r? @bholley
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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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Remove unused libc dependency for windows in style
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stylo: Allow computing change hints during the traversal.
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r? @bholley
cc @heycam
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In the Gecko case, this style source would be the style context. In the servo
case, it will be always the computed values.
We could optimise this further in the case of stylo (from three FFI calls to
one) if we use an API of the form CalcAndStore(node, new_cv). But that would
imply borrowing the data twice from Servo (we also have borrow_data_unchecked
fwiw, but...).
Add support for background-position in geckolib.
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r? @Manishearth
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