title: target=_blank doesn't work with GA outbound link tracking
body: <p>I want to track clicks on outbound links and implemented the following code:</p>
  
  <p><strong>GA code</strong></p>
  
  <pre><code>var trackOutboundLink = function(url) {
     ga('send', 'event', 'outbound', 'click', url, {'hitCallback':
       function () {
       document.location = url;
       }
     });
  }
  </code></pre>
  
  <p><strong>Links</strong></p>
  
  <pre><code>&lt;a class="postLinks" href="&lt;?php if (get_field('source_link')) echo get_field('source_link'); ?&gt;" onclick="trackOutboundLink('&lt;?php if (get_field("source_link")) echo get_field("source_link"); ?&gt;'); return false;"&gt;&lt;?php the_title(); ?&gt;&lt;/a&gt;
  </code></pre>
  
  <p><strong>target=_blank</strong></p>
  
  <p>I add the <code>target=_blank</code> attribute via jQuery based on whether the visitor to the website ticks a checkbox or not (the selection is then stored in a cookie). However, if I choose to open the outbound link in a new window it doesn't work. When ticking the checkbox it does correctly add the target attribute to the link but when I click on the link it opens it in the same window. </p>
  
  <p><strong>Links with target attribute</strong></p>
  
  <pre><code>&lt;a class="postLinks" href="&lt;?php if (get_field('source_link')) echo get_field('source_link'); ?&gt;" onclick="trackOutboundLink('&lt;?php if (get_field("source_link")) echo get_field("source_link"); ?&gt;'); return false;" target="_blank"&gt;&lt;?php the_title(); ?&gt;&lt;/a&gt;
  </code></pre>
  
  <p>Any idea?</p>