Remove warnings about WPT syncing process.
The process is well understood now and they're just annoying to remove every time.
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Add some support for WPT tests in an Android emulator through WebDriver
This succeeds on my machine:
`./mach test-wpt --product servodriver --binary etc/run_in_headless_android_emulator.py --binary-arg servo-x86 --binary-arg target/i686-linux-android/release/servo.apk /_mozilla/mozilla/DOMParser.html`
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Refactor run_in_headless_android_emulator.py out of mach test-android-startup
… and make it more careful about not leaving zombie processes behind.
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Support memory report logs with interleaved non-report output
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`line 30-31` in `servo/etc/memory_reports_over_time.py` should just ignore any line that doesn't begin with `|`.
The new if statement added such as `if line.startswith('|'):` then continue to append. So, only lines begin with `|` will be appended.
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- [X] `./mach test-tidy` does not report any errors
- [ ] These changes fix #20257(github issue number if applicable).
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