Incorrect geometry for OnMouseMove event on Slider with RightToLeft flow direction

When a slider is in RTL flow direction, and thus its position is changed, the handle is not drawn at the correct position during mouse drag.

Instead, the handle draws as if the slider was not moved by the RTL flow direction.

1. Download the Licensee's test project and open (see addl info URL)

1. Play PIE

1. Using the mouse, drag the slider at the top of the PIE window

1. Observe the slider handle is offset to the left