Remove unused code (1/N)
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First PR in a series of PRs to remove unused/dead code from servo, powered by an (upcoming) tool of mine. Please take a look and tell me if you want to keep something.
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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [ ] These changes fix #___ (GitHub issue number if applicable)
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- [ ] There are tests for these changes OR
- [x] These changes do not require tests because they only remove dead code
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`hb_font_funcs_set_glyph_h_kerning_func` is gone but I couldn't find any
replacement. Kerning tests are passing and kerning seems fine on my
computer so I guess it's useless now ?
Ensure transparent hit test region is sized and positioned correctly.
This addresses some edge cases that were missed by #22156. Specifically, in some cases the transparent region was being placed in the display list in front of the scrollable content, rather than behind it, and the size of the region did not account for parent stacking context.
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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#22073 and fix#22216.
- [x] There are tests for these changes
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Reduce unnecessary iframe size messages
This should be an improvement on pages that include iframes, since we currently run two layout jobs for every display-oriented layout request. When building the display list, we send a message to the constellation that includes the sizes of all iframes present, and the constellation sends resize messages to the script thread. This results in a mouse event on the outer page causing all frames to be re-laid out even if no changes occurred to the iframe sizes, which is ridiculous.
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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#22394
- [x] These changes do not require tests because there is no way to test this internal detail.
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