Bug 493357 - [gtk3] 8 tests consistently fail on CentOS

- Implementation without using SWT internal OS class
- Uses org.eclipse.swt.internal.gtk.version property to check for gtk3

Change-Id: Id11af5cb58696161122c61b641eaec2f54ef8d45
Signed-off-by: Sravan Kumar Lakkimsetti <sravankumarl@in.ibm.com>
diff --git a/tests/org.eclipse.ui.tests/Eclipse JFace Tests/org/eclipse/jface/tests/viewers/ListViewerRefreshTest.java b/tests/org.eclipse.ui.tests/Eclipse JFace Tests/org/eclipse/jface/tests/viewers/ListViewerRefreshTest.java
index bd36258..c4df609 100644
--- a/tests/org.eclipse.ui.tests/Eclipse JFace Tests/org/eclipse/jface/tests/viewers/ListViewerRefreshTest.java
+++ b/tests/org.eclipse.ui.tests/Eclipse JFace Tests/org/eclipse/jface/tests/viewers/ListViewerRefreshTest.java
@@ -19,7 +19,6 @@
 import org.eclipse.jface.viewers.StructuredSelection;
 import org.eclipse.jface.viewers.Viewer;
 import org.eclipse.swt.SWT;
-import org.eclipse.swt.internal.gtk.OS;
 import org.eclipse.swt.layout.FillLayout;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Label;
@@ -41,8 +40,12 @@
 
 	private ArrayList input = null;
 
+	protected boolean disableTestsBug493357 = false;
+
+
 	@Override
 	protected void setUp() throws Exception {
+		disableTestsBug493357 = System.getProperty("org.eclipse.swt.internal.gtk.version", "").startsWith("3."); // $NON-NLS-1//$NON-NLS-2//$NON-NLS-3
 		shell = new Shell();
 		shell.setSize(400, 200);
 		shell.setLayout(new FillLayout());
@@ -73,7 +76,7 @@
 	 * @throws Exception
 	 */
 	public void testNoSelectionRefresh() throws Exception {
-		if (OS.GTK3) {
+		if (disableTestsBug493357) {
 			System.out.println(getName() + " disabled due to Bug 493357");
 			return;
 		}
@@ -106,7 +109,7 @@
 	 * @throws Exception
 	 */
 	public void testSelectionRefresh() throws Exception {
-		if (OS.GTK3) {
+		if (disableTestsBug493357) {
 			System.out.println(getName() + " disabled due to Bug 493357");
 			return;
 		}
diff --git a/tests/org.eclipse.ui.tests/Eclipse JFace Tests/org/eclipse/jface/tests/viewers/ViewerTestCase.java b/tests/org.eclipse.ui.tests/Eclipse JFace Tests/org/eclipse/jface/tests/viewers/ViewerTestCase.java
index 98fc786..41a1572 100644
--- a/tests/org.eclipse.ui.tests/Eclipse JFace Tests/org/eclipse/jface/tests/viewers/ViewerTestCase.java
+++ b/tests/org.eclipse.ui.tests/Eclipse JFace Tests/org/eclipse/jface/tests/viewers/ViewerTestCase.java
@@ -22,7 +22,6 @@
 import org.eclipse.jface.viewers.StructuredSelection;
 import org.eclipse.jface.viewers.StructuredViewer;
 import org.eclipse.swt.SWT;
-import org.eclipse.swt.internal.gtk.OS;
 import org.eclipse.swt.layout.FillLayout;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Display;
@@ -46,7 +45,6 @@
 	public ViewerTestCase(String name) {
 		super(name);
 		disableTestsBug347491 = Util.isCocoa();
-		disableTestsBug493357 = OS.GTK3;
 	}
 
 	protected void assertSelectionEquals(String message, TestElement expected) {
@@ -111,6 +109,7 @@
 
 	@Override
 	public void setUp() {
+		disableTestsBug493357 = System.getProperty("org.eclipse.swt.internal.gtk.version", "").startsWith("3."); // $NON-NLS-1//$NON-NLS-2//$NON-NLS-3
 		oldLogger = Policy.getLog();
 		oldRunner = SafeRunnable.getRunner();
 		Policy.setLog(new ILogger(){