Move macOS WPT chunk 1 (only) from Buildbot to Taskcluster
This is only one chunk at a time so that we don’t need to double the number of worker nor the cycle time during the migration.
A release build takes ~40 minutes which seems worrying, but this also happens (sometimes) on Buildbot. For example: https://build.servo.org/builders/mac-rel-wpt1/builds/10401
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Tweak the Salt definition of /Library/LaunchAgents/net.generic.worker.plist
so that the `user` parameter for the template file is not taken
as a parameter for `file.managed`.
(The first run created a file owned by `worker` instead of `root`.)
Put every Android build artefact in target/android/
This works around #20380 at the cost of rebuilding build-only dependencies twice,
once for normal builds and once for android builds.
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Update the manifest twice to work around manifest generation issue.
My theory is that the new VCS-based cache that's used when generating the manifest gets confused when files that match a gitignore rule are added for the first time. Updating the manifest twice makes the problematic files disappear from the manifest, and I'm not inclined to spend any more time chasing this bug. Fixes#22275.
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Add background hang monitor
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Early feedback welcome, still need to ~~actually integrate it in the constellation message loop, and~~ use it in Layout and Script...
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- [ ] These changes fix#16740 (github issue number if applicable).
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