<Swing Dev> [10] RFR JDK-8173739: JPopupMenu does not disappear on KeyEvent

[Prasanta Sadhukhan]

Hi All,

Please review a fix for an issue where it is seen that if a popup menu 
is shown in an internal frame and
another internal frame is shown on top of 1st frame, then even though 
1st internal frame gets hidden, the popup is still visible.

Issue was popup menu was not getting cancelled when the 1st internal 
frame gets hidden/deactivated.
Poprosed fix is to send an UngrabEventwhen the 1st internal frame gets 
deactivated
  so that BasicPopupMenuUI can catch the UngrabEvent and cancel the 
popupmenu .

Bug: https://bugs.openjdk.java.net/browse/JDK-8173739
webrev: http://cr.openjdk.java.net/~psadhukhan/8173739/webrev.00/

Regards
Prasanta