diff -r 000000000000 -r 6474c204b198 mobile/android/base/sync/setup/activities/LocaleAware.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/sync/setup/activities/LocaleAware.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,59 @@
+/* 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.setup.activities;
+
+import org.mozilla.gecko.BrowserLocaleManager;
+import org.mozilla.gecko.LocaleManager;
+
+import android.annotation.TargetApi;
+import android.app.Activity;
+import android.content.Context;
+import android.os.Build;
+import android.os.Bundle;
+import android.os.StrictMode;
+import android.support.v4.app.FragmentActivity;
+
+/**
+ * This is a helper class to do typical locale switching operations
+ * without hitting StrictMode errors or adding boilerplate to common
+ * activity subclasses.
+ *
+ * Either call {@link LocaleAware#initializeLocale(Context)} in your
+ * <code>onCreate</code> method, or inherit from <code>LocaleAwareFragmentActivity</code>
+ * or <code>LocaleAwareActivity</code>.
+ */
+public class LocaleAware {
+  @TargetApi(Build.VERSION_CODES.GINGERBREAD)
+  public static void initializeLocale(Context context) {
+    final LocaleManager localeManager = BrowserLocaleManager.getInstance();
+    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.GINGERBREAD) {
+      localeManager.getAndApplyPersistedLocale(context);
+    } else {
+      final StrictMode.ThreadPolicy savedPolicy = StrictMode.allowThreadDiskReads();
+      StrictMode.allowThreadDiskWrites();
+      try {
+        localeManager.getAndApplyPersistedLocale(context);
+      } finally {
+        StrictMode.setThreadPolicy(savedPolicy);
+      }
+    }
+  }
+
+  public static class LocaleAwareFragmentActivity extends FragmentActivity {
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+      LocaleAware.initializeLocale(getApplicationContext());
+      super.onCreate(savedInstanceState);
+    }
+  }
+
+  public static class LocaleAwareActivity extends Activity {
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+      LocaleAware.initializeLocale(getApplicationContext());
+      super.onCreate(savedInstanceState);
+    }
+  }
+}