title: Chrome extension to read HTTP response
body: <p>I have this Chrome extension that modifies the header of requests before sending them. I now would like to be able, within the same extension, to check the header of the response. I searched throughout the Chrome Extension APIs but I couldn't find anything of interest.</p>
  
  <p>This is the code I use for modifying the header of the request, maybe it's useful for you to know how I do it.</p>
  
  <pre><code>chrome.webRequest.onBeforeSendHeaders.addListener(
        function(details) {/*do something*/},
        {urls: ["&lt;all_urls&gt;"]},
        ["blocking", "requestHeaders"]);
  </code></pre>
  
  <p>Does anyone knows how to do that, or can point me to an interesting source? Thanks</p>