DO NOT MERGE: Fix NPE in PhotoViewActivity

The fix is in UR9 already, so no need to auto-merge.

Bug: 8143282
Change-Id: Iaf072cec92072e5a8df852a31d8dafccf4115af7
diff --git a/src/com/android/ex/photo/PhotoViewActivity.java b/src/com/android/ex/photo/PhotoViewActivity.java
index fad1b31..f626757 100644
--- a/src/com/android/ex/photo/PhotoViewActivity.java
+++ b/src/com/android/ex/photo/PhotoViewActivity.java
@@ -182,6 +182,7 @@
         final Resources resources = getResources();
         mRootView = findViewById(R.id.photo_activity_root_view);
         mViewPager = (PhotoViewPager) findViewById(R.id.photo_view_pager);
+        mViewPager.setAdapter(mAdapter);
         mViewPager.setOnPageChangeListener(this);
         mViewPager.setOnInterceptTouchListener(this);
         mViewPager.setPageMargin(resources.getDimensionPixelSize(R.dimen.photo_page_margin));