title: How to get default value for DependencyProperty
body: <p>I have issue to set all controls values by button click to default. 
  Problem that this is not working when style is set. </p>
  
  <p>For example i have code:</p>
  
  <pre><code>               var metadata = dependencyProperty.DefaultMetadata;
  
                  if (value == null)
                  {
                      return metadata.DefaultValue == value;
                  }
                  else
                  {
                      return value.Equals(metadata.DefaultValue);
                  }
  </code></pre>
  
  <p>But this is not actually default properties! Because in styles can be other values set! 
  How to get really "default" proprties for control!? So WPF will also return value from style if such is set?</p>
  
  <p>P.s. ClearValue(propertyToClear); cannot be used because in some cases i need to check values.</p>