diff -r 000000000000 -r 6474c204b198 mobile/android/base/fxa/sync/FxAccountSyncStatusHelper.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/fxa/sync/FxAccountSyncStatusHelper.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,101 @@
+/* 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.fxa.sync;
+
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.WeakHashMap;
+
+import org.mozilla.gecko.fxa.FirefoxAccounts;
+import org.mozilla.gecko.fxa.authenticator.AndroidFxAccount;
+
+import android.content.ContentResolver;
+import android.content.SyncStatusObserver;
+
+/**
+ * Abstract away some details of Android's SyncStatusObserver.
+ * <p>
+ * Provides a simplified sync started/sync finished delegate.
+ */
+public class FxAccountSyncStatusHelper implements SyncStatusObserver {
+  @SuppressWarnings("unused")
+  private static final String LOG_TAG = FxAccountSyncStatusHelper.class.getSimpleName();
+
+  protected static FxAccountSyncStatusHelper sInstance = null;
+
+  public synchronized static FxAccountSyncStatusHelper getInstance() {
+    if (sInstance == null) {
+      sInstance = new FxAccountSyncStatusHelper();
+    }
+    return sInstance;
+  }
+
+  // Used to unregister this as a listener.
+  protected Object handle = null;
+
+  // Maps delegates to whether their underlying Android account was syncing the
+  // last time we observed a status change.
+  protected Map<FirefoxAccounts.SyncStatusListener, Boolean> delegates = new WeakHashMap<FirefoxAccounts.SyncStatusListener, Boolean>();
+
+  @Override
+  public synchronized void onStatusChanged(int which) {
+    for (Entry<FirefoxAccounts.SyncStatusListener, Boolean> entry : delegates.entrySet()) {
+      final FirefoxAccounts.SyncStatusListener delegate = entry.getKey();
+      final AndroidFxAccount fxAccount = new AndroidFxAccount(delegate.getContext(), delegate.getAccount());
+      final boolean active = fxAccount.isCurrentlySyncing();
+      // Remember for later.
+      boolean wasActiveLastTime = entry.getValue();
+      // It's okay to update the value of an entry while iterating the entrySet.
+      entry.setValue(active);
+
+      if (active && !wasActiveLastTime) {
+        // We've started a sync.
+        delegate.onSyncStarted();
+      }
+      if (!active && wasActiveLastTime) {
+        // We've finished a sync.
+        delegate.onSyncFinished();
+      }
+    }
+  }
+
+  protected void addListener() {
+    final int mask = ContentResolver.SYNC_OBSERVER_TYPE_ACTIVE;
+    if (this.handle != null) {
+      throw new IllegalStateException("Already registered this as an observer?");
+    }
+    this.handle = ContentResolver.addStatusChangeListener(mask, this);
+  }
+
+  protected void removeListener() {
+    Object handle = this.handle;
+    this.handle = null;
+    if (handle != null) {
+      ContentResolver.removeStatusChangeListener(handle);
+    }
+  }
+
+  public synchronized void startObserving(FirefoxAccounts.SyncStatusListener delegate) {
+    if (delegate == null) {
+      throw new IllegalArgumentException("delegate must not be null");
+    }
+    if (delegates.containsKey(delegate)) {
+      return;
+    }
+    // If we are the first delegate to the party, start listening.
+    if (delegates.isEmpty()) {
+      addListener();
+    }
+    delegates.put(delegate, Boolean.FALSE);
+  }
+
+  public synchronized void stopObserving(FirefoxAccounts.SyncStatusListener delegate) {
+    delegates.remove(delegate);
+    // If we are the last delegate leaving the party, stop listening.
+    if (delegates.isEmpty()) {
+      removeListener();
+    }
+  }
+}