[test] Mockpart: dispose titleImage

Author: EcljpseB0T

tests/org.eclipse.ui.tests/Eclipse UI Tests/org/eclipse/ui/tests/api/MockPart.java

@@ -126,6 +126,10 @@ public void createPartControl(Composite parent) {
 	 * @see IWorkbenchPart#dispose()
 	 */
 	public void dispose() {
+		if (titleImage != null) {
+			titleImage.dispose();
+			titleImage = null;
+		}
 		callTrace.add("dispose");
 	}