Print extensions attribute on open event.

R=yhirano@chromium.org

Review URL: https://codereview.appspot.com/16280047

src/example/console.html

diff --git a/src/example/console.html b/src/example/console.html
index 3a46bfd..de739be 100644
--- a/src/example/console.html
+++ b/src/example/console.html
@@ -144,11 +144,19 @@
   }
 
   socket.onopen = function () {
+    var extraInfo = [];
     if (('protocol' in socket) && socket.protocol) {
-      addToLog('Opened (protocol = ' + socket.protocol + ')');
-    } else {
-      addToLog('Opened');
+      extraInfo.push('protocol = ' + socket.protocol);
     }
+    if (('extensions' in socket) && socket.extensions) {
+      extraInfo.push('extensions = ' + socket.extensions);
+    }
+
+    var logMessage = 'Opened';
+    if (extraInfo.length > 0) {
+      logMessage += ' (' + extraInfo.join(', ') + ')';
+    }
+    addToLog(logMessage);
   };
   socket.onmessage = function (event) {
     if (('ArrayBuffer' in window) && (event.data instanceof ArrayBuffer)) {