Comment 2 for bug 1569315

There's multiple issues here:

1) Oxide is reading data from the clipboard every time the selection bounds change, in order to update the editing capability flags. This is really expensive (more than 50ms!)

2) Selections aren't always completely cancelled in Blink, and we continue to receive selection bounds updates with focus_rect == anchor_rect as content is scrolled.

3) Scrolling over active Flash content causes us to begin to receive selection bounds updates (again, with focus_rect == anchor_rect) as content is scrolled.