title: FrameLayout does not match the height of NestedScrollView
body: <p>I have a FrameLayout inside a NestedScrollView, as</p>
  
  <pre><code>&lt;android.support.v4.widget.NestedScrollView
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          app:layout_behavior="@string/appbar_scrolling_view_behavior"&gt;
  
          &lt;FrameLayout
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:background="#000000"&gt;
  </code></pre>
  
  <p>But the FrameLayout is not filling the height of the NestedScrollView. How might I fix this?</p>