Use 2018-edition idioms in crates that use that edition
The first commit is almost entirely mechanical, created by running `cargo fix --edition-idioms` and relevant crates. I undid the change of adding an anonymous lifetime parameter in types that have implicit lifetimes parameters, for example replacing `&mut Formatter` with `&mut Formatter<'_>`, because I don’t like it. The remaining changes are, in many places:
* Add `dyn` to trait object types, for example `Rc<gl::Gl>` to `Rc<dyn gl::Gl>`. This change also works in the 2015 edition.
* Remove `extern crate` where is it made unneeded by changes to the import/module system.
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HTMLMediaElement - use media element instead of dom manipulation task…
… source
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Connect to intermittent trackers via https
This is the last part of #22088.
Each https url returns the same with curl as its previous http variant, so it should be a safe change.
And https has already been used at this place in the past: 38474f8671
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Update Firefox version in user agent string
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GitHub is again limiting functionality in Servo due to using an outdated Firefox version in the user agent string. Updating this should get rid of the warning.
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Use line comments instead of block comments
as block comments contain trailing whitespace
after formatting with rustfmt.
Skip tests for malloc_size_of and script_plugins
with rustfmt as they have many block comments.
Add magicleap builder
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Add a magicleap builder to `etc/ci/buildbot_steps.yml` to gate releases on building the magicleap library. This doesn't yet check for building the magicleap app, or add a nightly release. That'll be a later PR.
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Count threads at shutdown, warn if not all finished and optionally block
On Desktop, after servo shutdown, the process exits, killing all the still-running threads.
On mobile, the process doesn't necessarily shutdown, and we are left with multiple threads failing to use channels, printing warning and panicking.
In the future, we'd like to do a clean shutdown, as in, shutdown only once all the threads have properly finished.
For now, I'm printing a warning if all the threads are not finished, and also add an option to only exit if all the threads have finished.
This only works on MacOS for now, in C, as I haven't found a Rust/multiplatform way to count running threads.
I recommend trying to run servo with `--clean-shutdown` option. Interesting to see how long it takes for other threads to shutdown, and see which threads start panicking.
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