title: How to get html meta data using flutter webview
body: <p>I need to get meta data from html head using flutter_webview.
  In this case I need to get value from</p>
  
  <pre><code>&lt;!-- Chrome, Firefox OS and Opera --&gt;
  &lt;meta name="theme-color" content="#4285f4"&gt;
  </code></pre>
  
  <p>so I can use website theme color on my app. </p>
  
  <p>how can I do this?</p>