Remove redundant `.clone()`s
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Removes `clone()`s of values unused after cloning.
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Add info about building on Linux Mint to README.md
Linux Mint 19.* is based on Ubuntu 16.04 packages.
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Cancel animations that affect nodes that do not participate in layout.
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- [x] These changes fix#22378
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Implement NavigationPreloadManager for ServiceWorker
---
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Minor pull request template cleanup
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Some minor changes to improve the consistency of the pull request template.
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Kill test processes whenever any error occurs
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Fixup the issue related with an incorrect distro version string handling
The original fixes for #21732 had a mistake.
The fix don't work on the LinuxMint with version 19:
```
File "./mach", line 96, in <module>
main(sys.argv)
File "./mach", line 24, in main
sys.exit(mach_bootstrap.bootstrap_command_only(topdir))
File "/home/user/workspace/skv/servo/python/mach_bootstrap.py", line 239, in bootstrap_command_only
bootstrap(context, force)
File "/home/user/workspace/skv/servo/python/servo/bootstrap.py", line 380, in bootstrap
distro, version = get_linux_distribution()
File "/home/user/workspace/skv/servo/python/servo/bootstrap.py", line 349, in get_linux_distribution
major, minor = version.split('.')
ValueError: need more than 1 value to unpack
```
I've fixed that
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Use the base Ubuntu distro instead of LinuxMint in './mach bootstrap'
I'm LinuxMint user.
I couldn't install all dependencies via `./mach bootstrap` due to error, described in this ticket: https://github.com/servo/servo/issues/21732
As LinuxMint is based on the stable Ubuntu, I've made a little fix for the `bootstrap` procedure.
---
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- [X] These changes fix#21732 (github issue number if applicable).
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Cleanup constellation after nll
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This cleans up a couple cases where we had to add extra scopes to appease the borrowck, now that nll has landed, this cleans these up.
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Update servo-media. Fixes discarded frames during player setup
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I'm pretty sure the FIXME I left in the outline-style code is a bug,
but I want to clean this up further and I didn't want to fix it without adding
a test.
Differential Revision: https://phabricator.services.mozilla.com/D12859
