PointerCapture by Custom Element's Shadow DOM

The magenta box below is part of a custom element's Shadow DOM.
Click left mouse button inside the box and keep mouse button depressed
Move the mouse
There should be a message stating Pointer was captured by custom element's Shadow DOM!
Release left mouse button
There should be a message stating Pointer was released by custom element's Shadow DOM!
Pointer was captured by custom element's Shadow DOM!
Pointer was released by custom element's Shadow DOM!

PASS PointerCapture works for custom element Shadow DOM.