diff -r 000000000000 -r 6474c204b198 mobile/android/base/sync/delegates/BaseGlobalSessionCallback.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/sync/delegates/BaseGlobalSessionCallback.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,42 @@
+/* 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.sync.delegates;
+
+import java.net.URI;
+
+import org.mozilla.gecko.sync.GlobalSession;
+import org.mozilla.gecko.sync.stage.GlobalSyncStage.Stage;
+
+public interface BaseGlobalSessionCallback {
+  /**
+   * Request that no further syncs occur within the next `backoff` milliseconds.
+   * @param backoff a duration in milliseconds.
+   */
+  void requestBackoff(long backoff);
+
+  /**
+   * Called on a 401 HTTP response.
+   */
+  void informUnauthorizedResponse(GlobalSession globalSession, URI oldClusterURL);
+
+
+  /**
+   * Called when an HTTP failure indicates that a software upgrade is required.
+   */
+  void informUpgradeRequiredResponse(GlobalSession session);
+
+  void handleAborted(GlobalSession globalSession, String reason);
+  void handleError(GlobalSession globalSession, Exception ex);
+  void handleSuccess(GlobalSession globalSession);
+  void handleStageCompleted(Stage currentState, GlobalSession globalSession);
+
+  /**
+   * Called when a {@link GlobalSession} wants to know if it should continue
+   * to make storage requests.
+   *
+   * @return false if the session should make no further requests.
+   */
+  boolean shouldBackOffStorage();
+}