Added GridSplitter example to XamlTestApplication, Layout tab.

samples/XamlTestApplicationPcl/Views/MainWindow.paml

@@ -220,6 +220,19 @@
                           <Rectangle Fill="Yellow" Height="25" DockPanel.Dock="Bottom" />
                           <Rectangle Fill="Pink" />
                       </DockPanel>
+                  
+                      <TextBlock Text="GridSplitter" FontWeight="Medium" FontSize="20" Foreground="#212121" />
+                      <Grid Height="500" Width="500" ColumnDefinitions="*,Auto,*,Auto,*" RowDefinitions="*,Auto,*">
+                         <Border Grid.Column="0" Grid.Row="0" Background="Red" />
+                         <HorizontalGridSplitter Grid.Column="0" Grid.Row="1" />
+                         <Border Grid.Column="0" Grid.Row="2" Background="Yellow" />
+                         <VerticalGridSplitter Grid.Column="1" Grid.RowSpan="3" />
+                         <Border Grid.Column="2" Grid.RowSpan="3" Background="Green" />
+                         <VerticalGridSplitter Grid.Column="3" Grid.RowSpan="3" />
+                         <Border Grid.Column="4" Grid.Row="0" Background="Blue" />
+                         <HorizontalGridSplitter Grid.Column="4" Grid.Row="1" />
+                         <Border Grid.Column="4" Grid.Row="3" Background="Pink" />
+                      </Grid>
                   </StackPanel>
               </ScrollViewer>
           </TabItem>