[10] Review request for 8186495: Some closed SQE tests fail after frame dispose() on Linux

[Semyon Sadetsky]

Hello,

Please review fix for JDK10:
bug: https://bugs.openjdk.java.net/browse/JDK-8186495

webrev: http://cr.openjdk.java.net/~ssadetsky/8186495/webrev.00/

After toolkit window is destroyed methods invocations on the window 
component may cause exceptions because of wrong native xwindow ID. The 
fix introduces checks in the X* peers to ensure that window ID is actual 
otherwise do nothing.

--Semyon