FULL PRODUCT VERSION :
java version "1.8.0_66"
Java(TM) SE Runtime Environment (build 1.8.0_66-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.66-b17, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Windows 7 x64

A DESCRIPTION OF THE PROBLEM :
https://bugs.openjdk.java.net/browse/JDK-8120120 

This bug is essentially to reopen the issue JDK-8120120 referenced by the url. 

In the 1.8.0_45 version, the functionality was that user entered value from the combo box is made available via getValue() when the field has lost focus. 

With 1.8.0_66 version, the behavior has reverted to having the user hit enter key. 

The details and discussions are same as the bug report JDK-8120120.

REGRESSION.  Last worked in version 8u45


REPRODUCIBILITY :
This bug can be reproduced always.