Initial webrtc and getUserMedia DOM support
This is able to reach the point where connections are properly negotiated and ready to exchange streams.
<s>The `toJSON()` stuff doesn't work yet, so most example code will need to be tweaked to manually construct JSON first before sending SDP and ICE messages over websockets. I'll add support for this soon. (This may need webidl tweaks to support `[Default]` and `toJSON()`)</s>
For some reason I haven't yet figured out, connections are one-way, Servo is able to receive streams but the other end doesn't see the streams Servo sends. I don't think this is due to https://github.com/servo/media/issues/191, but that bug is making it harder to test.
This implementation simply drops streams that it receives, without connecting them up to any output elements, since servo-media-player doesn't yet have mediastream support.
Since servo can neither effectively send nor receive streams this implementation isn't useful yet, however it is getting large and I figured I'd get it reviewed and landed early as a base.
r? @jdm
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Instructions for checking magicleap builds on linux
Needed to test a build failure, but couldn't on linux. This should be a
decent stop gap for now.
r? @asajeffrey
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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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Optional backtraces for JS errors and WebGL errors
This adds two new build-time features to enable useful debugging tools when investigating why JS and WebGL content isn't working. They're optional because they're quite heavyweight.
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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 do not require tests because they're optional developer features.
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Enable WebAudio on Android
- [X] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [X] These changes fix#21619
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Print the full path for errors occurring in the servo crate
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`Cargo` will print the path where it runs.
Origin python script `cd` into the crate folder, so the root path is set in the crate.
Now I use `--manifest-path PATH` to `cargo build`, so the root path is at `servo`.
Origin path in error message:
```
error: expected one of `!` or `::`, found `#`
--> lib.rs:24:1
```
Now it would be:
```
error: expected one of `!` or `::`, found `use`
--> ports/geckolib/glue.rs:11:1
```
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- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix#9895 (github issue number if applicable).
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