Windows: Selection in editable elements is cleared when scrolling using scrollbar

[David Bloom]

1. Create a selection in any editable element (<input>, designMode, contentEditable)
2. Click the scrollbar.

Expected: selection to be preserved
Actual: selection is lost

(This only affects Windows. The mouse scroll wheel does not cause loss of selection.)

[Jon@Chromium]

Also reported against Chromium, see http://code.google.com/p/chromium/issues/detail?id=5559 which includes a reduction, although for the reduction to work in Safari for Windows you need to increase the size of the font for the scrollbar to appear.

[Justin Garcia]

<rdar://problem/6560300>