title: Textblock.TextTrimming not working inside a grid
body: <p>I have a 3 column grid for my layout with each of it width set to <code>Width="*"</code>. For the middle (2nd) grid, I have another 3 column grid each containing it own textblock, and again the column grids width are set to <code>Width="*"</code>.</p>
  
  <p>When the Window is resized, the grids are resized as expected, however the 3rd textblock isn't getting trimmed if the text goes outside the boundary of the grid. I have textbox set with <code>TextTrimming="WordEllipsis"</code> and <code>TextWrapping="Wrap"</code>, and the properties are not being enforced for some reason.</p>
  
  <p>Here is some of the code I have:</p>
  
  <p>Layout grid:</p>
  
  <pre><code>&lt;Grid&gt;
      &lt;Grid.ColumnDefinitions&gt;
          &lt;ColumnDefinition MinWidth="150" MaxWidth="300" Width="1*" /&gt;
          &lt;ColumnDefinition Width="Auto"/&gt;
          &lt;ColumnDefinition MinWidth="150" MaxWidth="500" Width="1*" /&gt;
          &lt;ColumnDefinition Width="Auto"/&gt;
          &lt;ColumnDefinition Width="2*"/&gt;
      &lt;/Grid.ColumnDefinitions&gt;
  &lt;/Grid&gt;
  </code></pre>
  
  <p>2nd column code:</p>
  
  <pre><code>&lt;Grid Grid.Column="2" VerticalAlignment="Bottom" HorizontalAlignment="Left" Margin="5" Width="Auto"&gt;
      &lt;Grid.ColumnDefinitions&gt;
          &lt;ColumnDefinition Width="Auto" /&gt;
          &lt;ColumnDefinition Width="Auto" /&gt;
          &lt;ColumnDefinition Width="Auto" /&gt;
      &lt;/Grid.ColumnDefinitions&gt;
  
      &lt;TextBlock Text="{Binding Path=FeedItems.Count}" Foreground="White" FontSize="18" Width="Auto" FontWeight="SemiBold" /&gt;
      &lt;TextBlock Text=" items from " Foreground="White" FontSize="18" Width="Auto" Grid.Column="1" /&gt;
      &lt;TextBlock Text="{Binding Path=Name}" Foreground="White" FontSize="18" Grid.Column="2" TextTrimming="CharacterEllipsis" HorizontalAlignment="Left" Width="Auto" TextWrapping="NoWrap" ClipToBounds="True" /&gt;
  &lt;/Grid&gt;
  </code></pre>