Isolated XR Device Service

For a more thorough/high level overview of the entire WebXR stack, please refer to components/webxr.

Chromium's WebXR implementation makes use of the multiprocess architecture for added security. Thus all code which directly interfaces with and talks to the XR hardware ("runtimes") ends up loaded/hosted in a separate XR Utility process, except on Android where it runs in-process within the browser process (primarily to ensure access to and manipulation of Android SurfaceViews for rendering, and secondarily to minimize process overhead).

The XrDeviceService serves as the entry point for the VRServiceImpl in content/browser/xr to talk to this process, while the IsolatedXRRuntimeProvider is the main in-process entry point. The runtime provider continually polls for supported runtimes and, when a change is detected, creates and returns the appropriate runtime over Mojo. The Mojo interfaces used by this process are defined in device/vr.

Testing

This folder also defines test hooks. Tests can set this to modify the behavior of the IsolatedXRRuntimeProvider and force it to create a fake XR Device which the tests can fully control.