Definition
WebXR Device API defines XRWebGLLayer
[SecureContext, Exposed=Window]
interface XRWebGLLayer: XRLayer {
  constructor(XRSession session,
             XRWebGLRenderingContext context,
             optional XRWebGLLayerInit layerInit = {});
  // Attributes
  readonly attribute boolean antialias;
  readonly attribute boolean ignoreDepthValues;
  attribute float? fixedFoveation;
  [SameObject] readonly attribute WebGLFramebuffer? framebuffer;
  readonly attribute unsigned long framebufferWidth;
  readonly attribute unsigned long framebufferHeight;
  // Methods
  XRViewport? getViewport(XRView view);
  // Static Methods
  static double getNativeFramebufferScaleFactor(XRSession session);
};