[9] Review request for 8080137 Dragged events for extra mouse buttons (4, 5, 6) are not generated on JSplitPane

[Alexander Scherbatiy]

Hello,
Could you review the fix:
  bug: https://bugs.openjdk.java.net/browse/JDK-8080137
  webrev: http://cr.openjdk.java.net/~alexsch/8080137/webrev.00

  The LightweightDispatcher.isMouseGrab(MouseEvent) method does not 
take into account the extended modifiers for additional buttons.


Thanks,
Alexandr.