chromium/content/services/isolated_xr_device/README.md

# Isolated XR Device Service
_For a more thorough/high level overview of the entire WebXR stack, please refer to
[components/webxr](https://source.chromium.org/chromium/chromium/src/+/main:components/webxr/README.md)_

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 this is not possible. 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 mojom. The
mojom 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.