title: FloatingActionButton escapes the anchor view's bounds
body: <p>I have a layout like this:</p>
  
  <pre><code>&lt;CoordinatorLayout&gt;
      &lt;NestedScrollView
          android:id="@+id/contentScrollView
          android:layout_width="600dp"
          android:layout_Height="match_parent"
          android:fillViewport="true"
          app:layout_behavior="@string/appbar_scrolling_view_behavior"&gt;
  
          &lt;ViewStub
              android:id="@+id/viewStub"
              android:layout_width="match_parent"
              android:layout_height="match_parent" /&gt;
  
      &lt;/NestedScrollView&gt;
  
      &lt;FloatingActionButton
          android:id="@+id/fab"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_margin="16dp"
          app:layout_anchor="@id/contentScrollView"
          app:layout_anchroGravity="bottom|right|end" /&gt;
  &lt;/CoordinatorLayout&gt;
  </code></pre>
  
  <p>Now, the FAB works OK otherwise, but it escapes the bounds of the nested scroll view. It's aligned correctly with the bottom edge, but it's laid out right in the middle of the content's right edge (i.e. half of the FAB is inside the bounds while the other half is not).</p>
  
  <p>If the width of the nested scroll view is set to <code>match_parent</code>, it works correctly - and this is how it's laid out on phones. However, I want the scrolling content to be of constant width on tablets and the FAB should be inside the content, not outside of it.</p>
  
  <p>How do I set the FAB to be inside the bounds of the nested scroll view? Margins and paddings seem to do nothing about the horizontal alignment.</p>