Enable hybi WebSocket protocol by default.

chrome/test/data/extensions/api_test/websocket/test.html

 <script>
 chrome.test.runTests([
   function echoTest() {
     var ws = new WebSocket(
-        "ws://localhost:8880/websocket/tests/hixie76/workers/resources/echo");
+        "ws://localhost:8880/websocket/tests/hybi/workers/resources/echo");
     var MESSAGE_A = "message a";
     var MESSAGE_B = "message b";
 
     ws.onopen = function() {
       chrome.test.log("websocket opened.");
       ws.send(MESSAGE_A);
     };
 
     ws.onclose = function() {
       chrome.test.log("websocket closed.");
     }
 
     ws.onmessage = function(messageEvent) {
       chrome.test.log("message received: " + messageEvent.data);
       chrome.test.assertEq(MESSAGE_A, messageEvent.data);
 
       ws.onmessage = function(messageEvent) {
         chrome.test.log("message received: " + messageEvent.data);
         chrome.test.assertEq(MESSAGE_B, messageEvent.data);          
         ws.close();
 
         chrome.test.succeed();
       };
 
       ws.send(MESSAGE_B);
     };
   }
 ]);
 </script>