On the PC an EditorWindow Repaints before opening a context menu.
On a Mac the EditorWindow doesn't Repaint before opening a context menu.

This causes problems when you right click to both select and open a context menu. You want the selection to repaint before opening the context menu.

To reproduce:
- Open: Main Menu -> Window -> ContextMenuRepaintBug
- Note that you can click on the box to select it and off the box to deselect it
- Click off the box to deselect it
- Right click on the box to open a context menu:
- On a PC, the box is selected and the context menu opens (the expected behaviour).
- On a Mac, the box appears unselected when the context menu opens. After closing the context menu the box redraws to reflect its actual state.

Real world example: In Playmaker the graph view where you edit FSM states works fine on the PC, but has this repaint problem on Macs. I've tried lots of workarounds, but they all complicate the GUI code and have their own problems.