closed/javax/swing/JComboBox/4212498/bug4212498.java:Edit the value in the text field and then press the tab key, the number don't increase

Testsuite name:Swing Regression
Test name(s):closed/javax/swing/JComboBox/4212498/bug4212498.java
Product(s) tested:JDK 9 b40
OS/architecture:win7 sp1 x64

Error log file : http://aurora.ru.oracle.com/slot-gw/645468.ManualSubmit-1/workDir/closed/javax/swing/JComboBox/4212498/bug4212498.jtr

Reproducible: Always
Reproducible on machine: Evergreen-machine
[If Sometimes] Also reproducible on machine:

Is it a Regression: Yes
[If Regression] Regression introduced in release/build:
Test result on the last GAed release for this train: Pass (JDK 8u31 b10/win7 sp1 X64: Pass)
[if Fail] Test result on FCS:

Is it a platform specific issue: NO (JDK 9 b40/oel6.4 uek x64:Fail
                                                      JDK 9 b40/mac 10.9 x64:Fail)
[If platform specific issue] Is it a new (previously unsupported) OS/browser/mode testing: No
[If new configuration testing] Issue specific to execution mode or OS/browser version:

Steps to reproduce:
1. Download regression workspace from http://jre.us.oracle.com/java/re/jdk/9-jigsaw-m2/nightly/b40_2014-11-21-1021_1764/ws/jdk/test/ to C:/workspace/regression
2. Install test bundle JDK9b40 (download from http://jre.us.oracle.com/java/re/jdk/9-jigsaw-m2/nightly/b40_2014-11-21-1021_1764/bundles/) to C:/Java/jdk1.9.0
3. Install stable JDK7u45b18 (download from http://jre.us.oracle.com/java/re/jdk/7u45/promoted/fcs/b18/bundles/windows-x64/jdk-7u45-windows-x64.exe) to C:/Java/jdk1.7.0_45
4. Download and unzip Jtreg from http://jre.us.oracle.com/java/re/jtreg/4.1/promoted/fcs/b08/bundles/jtreg_bin-4.1.zip locate at C:/workspace/regression
5. Create the script regression.sh as follows and run it
 export JT_JAVA=C:/Java/jdk1.7.0_45
 C:/workspace/regression/jtreg/win32/bin/jtreg -v -m -ignore:quiet -jdk:C:/Java/jdk1.9.0 -r:C:/workspace/regression/results/reportDir -w:C:/workspace/regression/results/workDir C:/workspace/regression/test/closed/javax/swing/JComboBox/4212498/bug4212498.java

Case Instruction:
Edit the value in the text field (without using the popup) and then press the tab key. If the number increases then it passes. Also, try tabbing out without making a change. The number should NOT increase unless the user changes something.

Actual behavior:
 1. Edit the value in the text field and then press the tab key, the number don't increase.
 2. We also tried this case with the same build without jtreg tool, it has the same issue.