Memory usage of java process increases after pressing start button in test window

Testsuite name: Regression
JDK/JRE tested: JDK8b119(64bit)
OS/architecture: winvista sp2 x64
Reproducible: Always

Test run log location:
http://jsqalab.us.oracle.com/results/Evergreen/8/b119/regression/vista-sp2-x64/results-swing/workDir/javax/swing/JFileChooser/6798062/bug6798062.jtr

Steps to reproduce:
1.Download regression workspace from http://jre.sfbay.sun.com/java/re/jdk/8/promoted/ea/b119/ws/jdk/test to C:\regression\test

2. Install test bundle JDK8b119 (download from http://jre.us.oracle.com/java/re/jdk/8/promoted/ea/b119/bundles/windows-x64/jdk-8-ea-windows-x64.exe to C:\Java\jdk1.8.0

3.Install stablejdk 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/b02/bundles/jtreg_bin-4.1.zip locate at C:/regression/

5.Create the script regression.sh as follows and run it

export JT_JAVA=C:/Java/jdk1.7.0_45
C:/regression/jtreg/win32/bin/jtreg -v -m -ignore:quiet -jdk:C:/Java/jdk1.8.0 -r:C:/regression/results/reportDir -w:C:/regression/results/workDir C:/regression/test/javax/swing/JFileChooser/6798062/bug6798062.java

Instruction:
The test is suitable only for Windows

1. Create a link
2. Copy path to the link into TextField
3. Run the Windows Task Manager. Select the Processes tab and find the java process
4. Press the Start button in the test window
5. Wait several minutes and observe in the Windows Task Manager
that Memory Usage of java process is not increasing

Actual behavior:
Before pressing the Start button in the test window,the Windows Task Manager refer to 6798062_1.jpg.After pressing the button and waiting more than 20 mins,the memory Usage of java process is increasing,refer to 6798062_2.jpg.Then press Done,it is passed automatically.