title: Resize NSPopover after it is shown
body: <p>I have an NSPopover who's content in an NSView. I create the popover and add the view like this: </p>
  
  <pre><code>NSPopover *thePopover = [[NSPopover alloc] init];
  [thePopover setContentViewController:myViewController];
  </code></pre>
  
  <p>I then show the popover and set the size:</p>
  
  <pre><code>[thePopover setContentSize:NSMakeSize(300.0f, 160.0f)];
  </code></pre>
  
  <p>At this point the popover is visible and its content view is correct. Is there a way that I can resize the popover at this point without closing and re-showing it?</p>