--- a/jdk/src/share/classes/java/awt/image/ImageObserver.java	Wed Jul 05 18:09:43 2017 +0200
+++ b/jdk/src/share/classes/java/awt/image/ImageObserver.java	Thu Jun 07 18:05:09 2012 -0700
@@ -27,12 +27,16 @@
 
 import java.awt.Image;
 
+import javax.tools.annotation.GenerateNativeHeader;
+
 /**
  * An asynchronous update interface for receiving notifications about
  * Image information as the Image is constructed.
  *
  * @author      Jim Graham
  */
+/* No native methods here, but the constants are needed in the supporting JNI code */
+@GenerateNativeHeader
 public interface ImageObserver {
     /**
      * This method is called when information about an image which was