title: Get "ascent" LineHeight from Font
body: <p>How can get the LineHeight of a Font given the FontSize?  It seems that it is different depending on the font and not necessarily connected to the FontSize.  I am using BlockLineHeight for the LineStackingStrategy.</p>
  
  <p><strong>Clarification.</strong>  I understand there are methods of determining the total line height.  In this case, I'm looking for the height from the baseline to the top of the font (so minus the tails of the p's etc.)</p>
  
  <p><img src="https://i.stack.imgur.com/JMRg1.jpg" alt="enter image description here"></p>
  
  <p>In the case of the picture above.  I want the ascent.</p>