6862611: Reg testcase closed/java/awt/Component/NativeInLightShow/NativeInLightShow.html fails

Summary: The recursiveShowHeavyweightChildren() must be invoked unconditionally in mixOnShowing()
Reviewed-by: art, dcherepanov

src/share/classes/java/awt/Container.java

@@ -4111,16 +4111,16 @@ public class Container extends Component {
                 mixingLog.fine("this = " + this);
             }
 
-            if (!isMixingNeeded()) {
-                return;
-            }
-
             boolean isLightweight = isLightweight();
 
             if (isLightweight && isRecursivelyVisibleUpToHeavyweightContainer()) {
                 recursiveShowHeavyweightChildren();
             }
 
+            if (!isMixingNeeded()) {
+                return;
+            }
+
             if (!isLightweight || (isLightweight && hasHeavyweightDescendants())) {
                 recursiveApplyCurrentShape();
             }