chromium/chrome/test/data/settings/protocol_handler.html

<html>
  <head>
    <title>Protocol Handler Test - Register</title>
      <script type="text/javascript">
        function registerCustomHandler() {
          var custom_protocol = "web+search";
          var query_value = custom_protocol + ":test";
          var query_key = "q";
          var url = document.URL + "?" + query_key + "=%s";
          var title = "Example Search";

          navigator.registerProtocolHandler(
              custom_protocol, url, title);
          var element = document.getElementById('test_protocol');
          element.innerText = query_value;
          element.setAttribute('href', query_value);

          return {"protocol": custom_protocol, "url": url, "title": title,
            "query_key": query_key, "query_value": query_value};
        }

        function registerMailClient() {
          var mail_protocol = "mailto";
          var query_value = mail_protocol + ":[email protected]";
          var query_key = "source";
          var url = document.URL + "?" + query_key + "=%s";
          var title = "ExampleMailClient";

          navigator.registerProtocolHandler(mail_protocol, url, title);
          return {"protocol": mail_protocol, "url": url, "title": title,
                  "query_key": query_key, "query_value": query_value};
        }

        // Analyzes the query substring (if any) of the URL and confirms
        // whether it's expected.
        function doesQueryConformsToProtocol(query_key, query_value) {
          var query = window.location.search.substring(1);
          var arg_list = query.split("&");

          if(arg_list.length != 1) return false;
            var variable_value = arg_list[0].split("=");
            if((variable_value[0] != query_key) ||
              (unescape(variable_value[1]) != query_value))
              return false;
          return true;
        }
      </script>
  </head>
  <body>
    <div>
      <a id="test_protocol"></a>
    </div>
    <div>
      <a id="test_mail_protocol" href="mailto:[email protected]">mailto:[email protected]</a>
    </div>
  </body>
</html>