Cancel client auth requests when not promptable.

content/test/data/workers/worker_common.js

Index: content/test/data/workers/worker_common.js
diff --git a/content/test/data/workers/worker_common.js b/content/test/data/workers/worker_common.js
index 675de0de6d1b8fb4b59bee4151e440f86e25e41f..6a9e6b15609b03e4b7cf30b89d8d9e3edfa9d95d 100644
--- a/content/test/data/workers/worker_common.js
+++ b/content/test/data/workers/worker_common.js
@@ -29,5 +29,11 @@ onmessage = function(evt) {
     } catch (ex) {
       postMessage(ex);
     }
+  } else if (/tls-client-auth.+/.test(evt.data)) {
+    try {
+      importScripts(evt.data.substr(16));
+    } catch (ex) {
+    }
+    postMessage("done");
   }
 }