title: Change browser preferences in runtime?
body: <p>Can we change browser preferences in runtime?</p>
  
  <p>Is there any possibility to changes the browser preferences set before launching the browser during execution programmatically?</p>
  
  <p>Example:</p>
  
  <p>I have set the following preferences before launching the driver </p>
  
  <pre><code>firefoxProfile.setPreference("pdfjs.disabled", true);
  firefoxProfile.setPreference("plugin.scan.plid.all", false);
  firefoxProfile.setPreference("plugin.scan.Acrobat", "99.0");
  </code></pre>
  
  <p>I want to change the preference to :</p>
  
  <pre><code>firefoxProfile.setPreference("pdfjs.disabled", **false**);
  firefoxProfile.setPreference("plugin.scan.plid.all", **true**);
  firefoxProfile.setPreference("plugin.scan.Acrobat", "99.0");
  </code></pre>
  
  <p>Please help!!</p>
  
  <p>Thanks</p>