diff -r 000000000000 -r 6474c204b198 mobile/android/base/tokenserver/TokenServerClientDelegate.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/tokenserver/TokenServerClientDelegate.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,19 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.tokenserver;
+
+
+public interface TokenServerClientDelegate {
+  void handleSuccess(TokenServerToken token);
+  void handleFailure(TokenServerException e);
+  void handleError(Exception e);
+
+  /**
+   * Might be called multiple times, in addition to the other terminating handler methods.
+   */
+  void handleBackoff(int backoffSeconds);
+
+  public String getUserAgent();
+}