ViewPager API update

Change-Id: I3033caefc206c969f172b2dd0e76809a21c15652
diff --git a/samples/Support13Demos/src/com/example/android/supportv13/app/ActionBarTabsPager.java b/samples/Support13Demos/src/com/example/android/supportv13/app/ActionBarTabsPager.java
index 6c0f803..433f7e9 100644
--- a/samples/Support13Demos/src/com/example/android/supportv13/app/ActionBarTabsPager.java
+++ b/samples/Support13Demos/src/com/example/android/supportv13/app/ActionBarTabsPager.java
@@ -135,6 +135,10 @@
         }
 
         @Override
+        public void onPageScrollStateChanged(int state) {
+        }
+
+        @Override
         public void onTabSelected(Tab tab, FragmentTransaction ft) {
             Object tag = tab.getTag();
             for (int i=0; i<mTabs.size(); i++) {