Should bars in HTML progress, meter & input=range elements be read upwards or downwards in vertical text?

[r12a]

Background

This question was prompted by the HTML issue at whatwg/html#8413

Currently, Blink and WebKit don't make these inline controls vertical (see w3c/clreq#247).

Gecko, however, does display the control vertically, but the reading direction of the bar when progress or meter or input=range elements are used in HTML is bottom to top.

Test for all

Question

Is it preferable for the direction of the control to follow the direction of the surrounding text (ie. start at the top of the control), or should it always progress from bottom to top?