Auto merge of #23546 - asajeffrey:magicleap-webvr-second-cut, r=Manishearth

Add Servo3D immersive demo for magicleap

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An immersive mode demo for magicleap.

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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors (apart from dupes, sigh)
- [X] These changes fix #22402 (GitHub issue number if applicable)
- [X] These changes do not require tests because it's a new platform

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components/script/dom/window.rs

@@ -1436,7 +1436,7 @@ impl Window {
 
         let complete = match join_port.try_recv() {
             Err(TryRecvError::Empty) => {
-                info!("script: waiting on layout");
+                debug!("script: waiting on layout");
                 join_port.recv().unwrap()
             },
             Ok(reflow_complete) => reflow_complete,