Fix warning about using static directly in tests

Author: akurtakov

tests/org.eclipse.swt.tests/data/clipboard/ClipboardTest.java

@@ -31,6 +31,7 @@
 import javax.swing.JScrollPane;
 import javax.swing.JTextArea;
 import javax.swing.SwingUtilities;
+import javax.swing.WindowConstants;
 
 import org.eclipse.swt.tests.junit.Test_org_eclipse_swt_dnd_Clipboard;
 
@@ -96,7 +97,7 @@ public ClipboardTest() throws RemoteException {
 		add(scrollPane, BorderLayout.CENTER);
 		add(buttonPanel, BorderLayout.SOUTH);
 
-		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+		setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
 		pack();
 		setLocationRelativeTo(null); // Center on screen
 		setVisible(true);