Context

This issue introduces the Pointer Progress Timelines. These timelines are linked to progress in the pointer position over an element’s principal box along a particular axis.

The module defines two concepts to specify this progress:
pointer range: the size of the element’s principal box along the axis of the pointer progress timeline.
pointer offset: the position of the pointer relative to the start of the element’s pointer range.

As currently specced, the pointer range is as defined by offsetX and offsetY in cssom-view-1, meaning that the padding edges of the element’s principal box are used to define the start and end points of the timeline.
If necessary, we can later add sub-properties to change/extend that definition or add insets.

Proposal

Accept spec text that follows pointer events and uses padding edges by default.