8000486: REGRESSION: Three java2d tests fail since jdk8b58 on Windows 7 with NullPointerException

Reviewed-by: flar, art

src/windows/classes/sun/java2d/ScreenUpdateManager.java

@@ -111,7 +111,7 @@ public class ScreenUpdateManager {
                                                    SurfaceData oldsd)
     {
         SurfaceData surfaceData = peer.getSurfaceData();
-        if (surfaceData.isValid()) {
+        if (surfaceData == null || surfaceData.isValid()) {
             return surfaceData;
         }
         peer.replaceSurfaceData();