Bug 1564635 [wpt PR 17538] - Update interfaces/webxr.idl, a=testonly

Automatic update from web-platform-tests
Update interfaces/webxr.idl (#17538)

Source: https://github.com/tidoust/reffy-reports/blob/64138b3/whatwg/idl/webxr.idl
Build: https://travis-ci.org/tidoust/reffy-reports/builds/551049210
--

wpt-commits: 70e20022f311052672b86d30ab0895c1c276c72e
wpt-pr: 17538

testing/web-platform/tests/interfaces/webxr.idl

@@ -171,6 +171,7 @@ interface XRInputSource {
   [SameObject] readonly attribute XRSpace targetRaySpace;
   [SameObject] readonly attribute XRSpace? gripSpace;
   [SameObject] readonly attribute Gamepad? gamepad;
+  [SameObject] readonly attribute FrozenArray<DOMString> profiles;
 };
 
 [SecureContext, Exposed=Window]