Fix renderdemo sidebar template.

samples/RenderDemo/SideBar.xaml

@@ -1,5 +1,5 @@
 <Styles xmlns="https://github.com/avaloniaui"
-        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" >
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
     <Style Selector="TabControl.sidebar">
         <Setter Property="TabStripPlacement" Value="Left"/>
         <Setter Property="Padding" Value="8 0 0 0"/>
@@ -17,7 +17,7 @@
                             VerticalScrollBarVisibility="{TemplateBinding (ScrollViewer.VerticalScrollBarVisibility)}"
                             Background="{TemplateBinding Background}">
                             <ItemsPresenter
-                                Name="PART_ItemsPresenter"                                                            
+                                Name="PART_ItemsPresenter"                          
                                 Items="{TemplateBinding Items}"
                                 ItemsPanel="{TemplateBinding ItemsPanel}"
                                 ItemTemplate="{TemplateBinding ItemTemplate}"
@@ -25,7 +25,7 @@
                             </ItemsPresenter>
                         </ScrollViewer>
                         <ContentPresenter
-                            Name="PART_Content"
+                            Name="PART_SelectedContentHost"
                             Margin="{TemplateBinding Padding}"                           
                             HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
                             VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"
@@ -63,4 +63,4 @@
     <Style Selector="TabControl.sidebar > TabItem:selected /template/ ContentPresenter#PART_ContentPresenter">
         <Setter Property="Background" Value="{DynamicResource ThemeAccentBrush2}"/>
     </Style>
-</Styles>
+</Styles>