title: Floating action button not visible on scrolling after updating Google Support & Design Library
body: <p>I've tried updating <code>com.android.support:appcompat</code> and <code>com.android.support:design</code> from: 25.0.1 to 25.1.0, as follows:</p>
  
  <pre><code>compile 'com.android.support:appcompat-v7:25.0.1'
  compile 'com.android.support:design:25.0.1'
  </code></pre>
  
  <p>to:</p>
  
  <pre><code>compile 'com.android.support:appcompat-v7:25.1.0'
  compile 'com.android.support:design:25.1.0'
  </code></pre>
  
  <p>but I have found that my floating action button no longer appears when the activity scrolls.  My FAB behaviour is defined by the following:</p>
  
  <pre><code>public class MyFabBehavior extends FloatingActionButton.Behavior {
  
      public MyFabBehavior(Context context, AttributeSet attrs) {
          super();
      }
  
      @Override
      public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout,
                                         FloatingActionButton child, View directTargetChild, View target, int nestedScrollAxes) {
  
          // Ensure we react to vertical scrolling
          return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL
                  || super.onStartNestedScroll(coordinatorLayout, child, directTargetChild, target, nestedScrollAxes);
  
      }
  
      @Override
      public void onNestedScroll(CoordinatorLayout coordinatorLayout, FloatingActionButton child,
                                 View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed) {
  
          super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed);
          if (dyConsumed &lt; 0) {
              // User scrolled up -&gt; hide the FAB
              animateFab(child, View.GONE);
          } else if (dyConsumed &gt; 0) {
              // User scrolled down -&gt; show the FAB
              animateFab(child, View.VISIBLE);
          }
      }
  
      static public void animateFab(FloatingActionButton fab, int visibility) {
          // ignore visibility passed in, and just make fab visible regardless
          if (fab.getVisibility() != View.VISIBLE) {
              fab.show();
          }
      }
  }
  </code></pre>
  
  <p>and my layout is as follows:</p>
  
  <pre><code>&lt;android.support.design.widget.CoordinatorLayout
      android:layout_width="match_parent"
      android:layout_height="wrap_content"  &gt;
  
      &lt;android.support.v4.widget.NestedScrollView
          android:id="@+id/main_scrollview"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:orientation="vertical"
          android:padding="8dp" &gt;
  
          ...
  
      &lt;/android.support.v4.widget.NestedScrollView&gt;
  
      &lt;android.support.design.widget.FloatingActionButton
          app:layout_behavior="com.example.MyFabBehavior"
          android:id="@+id/fab"
          app:fabSize="normal"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_gravity="bottom|end"
          android:layout_marginBottom="@dimen/fab_margin"
          android:layout_marginRight="@dimen/fab_margin"
          android:onClick="saveButton"
          app:elevation="6dp"
          app:pressedTranslationZ="12dp"
          app:backgroundTint="@color/colorPrimary"
          android:src="@drawable/ic_done_white_24dp" /&gt;
  
  &lt;/android.support.design.widget.CoordinatorLayout&gt;
  </code></pre>