No longer support actions on timeline view.

src/action-handler-directive.ts

@@ -147,9 +147,6 @@ class ActionHandler extends HTMLElement implements ActionHandler {
     element.addEventListener('mousedown', start, { passive: true });
     element.addEventListener('click', end);
 
-    // For the timeline which generates native pointer events.
-    element.addEventListener('pointerdown', start, { passive: true });
-
     element.addEventListener('keyup', handleEnter);
   }
 }