UI component being attempted to be disposed in a non-ui thread. Updated

as per review comments.

Author: deepika-u

bundles/org.eclipse.ui.workbench/eclipseui/org/eclipse/ui/internal/e4/compatibility/CompatibilityPart.java

@@ -32,6 +32,7 @@
 import org.eclipse.e4.ui.di.Focus;
 import org.eclipse.e4.ui.di.Persist;
 import org.eclipse.e4.ui.di.PersistState;
+import org.eclipse.e4.ui.di.UISynchronize;
 import org.eclipse.e4.ui.internal.workbench.Activator;
 import org.eclipse.e4.ui.internal.workbench.Policy;
 import org.eclipse.e4.ui.model.application.ui.basic.MPart;
@@ -418,9 +419,13 @@ public void create() {
 	}
 
 	@PreDestroy
-	void destroy() {
+	void destroy(UISynchronize sync) {
 		if (!alreadyDisposed) {
-			invalidate();
+			sync.syncExec(() -> {
+				if (!alreadyDisposed) {
+					invalidate();
+				}
+			});
 		}
 
 		eventBroker.unsubscribe(widgetSetHandler);