PopupWindow position must be specified in window coordinates.

This CL addresses TODOs in Ib641dda49f7ab1c7d60207c36a47767bb408.

With this CL the position of PopupWindow is always specified in
window-local coordinates even if FloatingToolbar#mParent is not a
decor view.

Bug: 22335001
Change-Id: I0cdd63a00051fa30981e517c07682075467ac598
1 file changed