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This PR adds a replacement option when navigating. It replaces the current session history entry after a new page has been loaded. This will prevent reloading from adding a new entry to the session history.
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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#13123 (github issue number if applicable).
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- [X] There are tests for these changes OR
- [ ] These changes do not require tests because _____
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Source-Repo: https://github.com/servo/servo
Source-Revision: 9876923b29ae7c4f2b763e368fc34fe8a051afc4