title: Stretch content of SplitView.Pane when SplitView is in Compact mode
body: <p>I'm trying to create a navigation bar using the SplitView control. I set it's DisplayMode property to CompactInline and two different values for CompactPaneLength and OpenPaneLength properties.
  Problem is when SplitView gets closed (compacted), content of it's Pane won't be aware of new size so if I put a let's say Border element in it, the element won't be stretched and goes out of the compact pane area:</p>
  
  <pre><code> &lt;Grid Background="{StaticResource ApplicationPageBackgroundThemeBrush}"&gt;
      &lt;SplitView IsPaneOpen="False" CompactPaneLength="100" OpenPaneLength="200" DisplayMode="CompactInline"&gt;
          &lt;SplitView.Pane&gt;
              &lt;Border BorderBrush="Blue" Height="50"
                      BorderThickness="4"
                      VerticalAlignment="Top"&gt;
                  &lt;FontIcon Glyph="&amp;#xE094;"
                            Width="40"
                            Height="40" /&gt;
              &lt;/Border&gt;
          &lt;/SplitView.Pane&gt;
      &lt;/SplitView&gt;
  &lt;/Grid&gt;
  </code></pre>
  
  <p>Here is an image demonstrates the problem:</p>
  
  <p><img src="https://i.stack.imgur.com/34xpK.png" alt="SplitView Pane"></p>
  
  <p>Question is: How to solve the problem without using the event handlers and code behind?</p>