title: Return string from HttpRequest
body: <p>In Dart I can do:</p>
  
  <pre><code>await HttpRequest.getString(path)
  </code></pre>
  
  <p>and this will return a string.</p>
  
  <p>I want to create a method that will do the same, but like this:</p>
  
  <pre class="lang-dart prettyprint-override"><code>HttpRequest request = new HttpRequest();
  request
      ..open('Get',getPath)
      ..setRequestHeader('Content-Type','application/json')
      ..send('');
  ...
  return responseString;
  </code></pre>
  
  <p>I can do it using events and futures, but I would like to understand how to do it with async &amp; await specifically.</p>
  
  <p>Edit:
  This is for the dart:html HttpRequest for browser.</p>