diff -r 000000000000 -r 6474c204b198 mobile/android/base/sync/SharedPreferencesNodeAssignmentCallback.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/sync/SharedPreferencesNodeAssignmentCallback.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,63 @@
+/* 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;
+import java.net.URI;
+import java.net.URISyntaxException;
+
+import org.mozilla.gecko.sync.delegates.NodeAssignmentCallback;
+
+import android.content.SharedPreferences;
+import android.content.SharedPreferences.Editor;
+
+public class SharedPreferencesNodeAssignmentCallback implements NodeAssignmentCallback {
+  protected final SharedPreferences sharedPreferences;
+  protected final String nodeWeaveURL;
+
+  public SharedPreferencesNodeAssignmentCallback(SharedPreferences sharedPreferences, String nodeWeaveURL)
+      throws SyncConfigurationException {
+    this.sharedPreferences = sharedPreferences;
+    if (nodeWeaveURL == null) {
+      throw new IllegalArgumentException("nodeWeaveURL must not be null");
+    }
+    try {
+      new URI(nodeWeaveURL);
+    } catch (URISyntaxException e) {
+      throw new SyncConfigurationException();
+    }
+    this.nodeWeaveURL = nodeWeaveURL;
+  }
+
+  public synchronized boolean getClusterURLIsStale() {
+    return sharedPreferences.getBoolean(SyncConfiguration.PREF_CLUSTER_URL_IS_STALE, false);
+  }
+
+  public synchronized void setClusterURLIsStale(boolean clusterURLIsStale) {
+    Editor edit = sharedPreferences.edit();
+    edit.putBoolean(SyncConfiguration.PREF_CLUSTER_URL_IS_STALE, clusterURLIsStale);
+    edit.commit();
+  }
+
+  @Override
+  public boolean wantNodeAssignment() {
+    return getClusterURLIsStale();
+  }
+
+  @Override
+  public void informNodeAuthenticationFailed(GlobalSession session, URI failedClusterURL) {
+    // TODO: communicate to the user interface that we need a new user password!
+    // TODO: only freshen the cluster URL (better yet, forget the cluster URL) after the user has provided new credentials.
+    setClusterURLIsStale(false);
+  }
+
+  @Override
+  public void informNodeAssigned(GlobalSession session, URI oldClusterURL, URI newClusterURL) {
+    setClusterURLIsStale(false);
+  }
+
+  @Override
+  public String nodeWeaveURL() {
+    return this.nodeWeaveURL;
+  }
+}