Make Advanceable a public API.

Author: mikejurka

api/current.txt

@@ -26608,7 +26608,7 @@ package android.widget {
     method public abstract void onNothingSelected(android.widget.AdapterView<?>);
   }
 
-  public abstract class AdapterViewAnimator extends android.widget.AdapterView {
+  public abstract class AdapterViewAnimator extends android.widget.AdapterView implements android.widget.Advanceable {
     ctor public AdapterViewAnimator(android.content.Context);
     ctor public AdapterViewAnimator(android.content.Context, android.util.AttributeSet);
     ctor public AdapterViewAnimator(android.content.Context, android.util.AttributeSet, int);
@@ -26650,6 +26650,11 @@ package android.widget {
     method public void stopFlipping();
   }
 
+  public abstract interface Advanceable {
+    method public abstract void advance();
+    method public abstract void fyiWillBeAdvancedByHostKThx();
+  }
+
   public class AlphabetIndexer extends android.database.DataSetObserver implements android.widget.SectionIndexer {
     ctor public AlphabetIndexer(android.database.Cursor, int, java.lang.CharSequence);
     method protected int compare(java.lang.String, java.lang.String);

core/java/android/widget/Advanceable.java

@@ -21,7 +21,6 @@
  * progressing through its set of children. The interface exists to give AppWidgetHosts a way of
  * taking responsibility for automatically advancing such collections.
  *
- * @hide
  */
 public interface Advanceable {