title: Set (keyboard)focus to parent container when child with (keyboard)focus is removed
body: <p>I have two buttons in a canvas (with Focusable=true)
  I use the tab key to select one button and press enter to remove the button
  I want (keyboard)focus to go back to canvas, but it goes to window</p>
  
  <p>Demo:
  MainWindow.xaml</p>
  
  <pre><code>&lt;Window x:Class="WpfApplication1.MainWindow"
          xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
          xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
          xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
          xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
          xmlns:local="clr-namespace:WpfApplication1"
          mc:Ignorable="d"
          Title="MainWindow" Height="350" Width="525"&gt;
      &lt;Grid&gt;
          &lt;Grid.Resources&gt;
              &lt;Style TargetType="Button"&gt;
                  &lt;Setter Property="Background" Value="Red" /&gt;
                  &lt;Style.Triggers&gt;
                      &lt;Trigger Property="IsKeyboardFocused" Value="True"&gt;
                          &lt;Setter Property="Background" Value="Green" /&gt;
                      &lt;/Trigger&gt;
                  &lt;/Style.Triggers&gt;
              &lt;/Style&gt;
              &lt;Style TargetType="Canvas"&gt;
                  &lt;Setter Property="Background" Value="Red" /&gt;
                  &lt;Style.Triggers&gt;
                      &lt;Trigger Property="IsKeyboardFocused" Value="True"&gt;
                          &lt;Setter Property="Background" Value="Green" /&gt;
                      &lt;/Trigger&gt;
                  &lt;/Style.Triggers&gt;
              &lt;/Style&gt;
          &lt;/Grid.Resources&gt;
          &lt;Canvas Name="Canvas" Focusable="True"&gt;
              &lt;Button Click="RemoveSelf"&gt;Button 1&lt;/Button&gt;
              &lt;Button Canvas.Left="100" Click="RemoveSelf"&gt;Button 2&lt;/Button&gt;
          &lt;/Canvas&gt;
      &lt;/Grid&gt;
  &lt;/Window&gt;
  </code></pre>
  
  <p>MainWindow.xaml.cs:</p>
  
  <pre><code>using System.Windows;
  
  namespace WpfApplication1
  {
      /// &lt;summary&gt;
      /// Interaction logic for MainWindow.xaml
      /// &lt;/summary&gt;
      public partial class MainWindow
      {
          public MainWindow()
          {
              InitializeComponent();
          }
  
          private void RemoveSelf(object sender, RoutedEventArgs e)
          {
              Canvas.Children.Remove((UIElement)sender);
          }
      }
  }
  </code></pre>
  
  <p>When the application starts, everything is red.
  As soon as you press TAB, canvas becomes green
  Press TAB again, and Button 1 becomes green, canvas becomes red
  Press ENTER, button 1 disappears but canvas does not become green
  I want canvas to become green</p>