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The field ServoParser::pending_input should be a DOMRefCell<VeqDeque<String>>, this lets us use VecDeque::pop_front instead of Vec::remove in ServoParser::take_next_input_chunk.
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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#13690 (github issue number if applicable).
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- [ ] There are tests for these changes OR
- [ ] These changes do not require tests because _____
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…_input
Source-Repo: https://github.com/servo/servo
Source-Revision: 0b697c108001f70cf0a2aca4855815e579be6838
