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This is the Servo part of bug 1411469.
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<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix Mozilla bug 1411469
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- [ ] There are tests for these changes OR
- [X] These changes do not require tests because tests are on the Gecko side.
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r? @emilio
Source-Repo: https://github.com/servo/servo
Source-Revision: 10813436b36323711430ab56fad83234029c9f96
456014263b