diff -r 000000000000 -r 6474c204b198 mobile/android/tests/background/junit3/src/sync/TestSyncConfiguration.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/tests/background/junit3/src/sync/TestSyncConfiguration.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,145 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+package org.mozilla.gecko.background.sync;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.mozilla.gecko.background.helpers.AndroidSyncTestCase;
+import org.mozilla.gecko.sync.SyncConfiguration;
+
+import android.content.SharedPreferences;
+
+public class TestSyncConfiguration extends AndroidSyncTestCase {
+  public static final String TEST_PREFS_NAME = "test";
+
+  public SharedPreferences getPrefs(String name, int mode) {
+    return this.getApplicationContext().getSharedPreferences(name, mode);
+  }
+
+  /**
+   * Ensure that declined engines persist through prefs.
+   */
+  public void testDeclinedEngineNames() {
+    SyncConfiguration config = null;
+    SharedPreferences prefs = getPrefs(TEST_PREFS_NAME, 0);
+
+    config = newSyncConfiguration();
+    config.declinedEngineNames = new HashSet<String>();
+    config.declinedEngineNames.add("test1");
+    config.declinedEngineNames.add("test2");
+    config.persistToPrefs();
+    assertTrue(prefs.contains(SyncConfiguration.PREF_DECLINED_ENGINE_NAMES));
+    config = newSyncConfiguration();
+    Set<String> expected = new HashSet<String>();
+    for (String name : new String[] { "test1", "test2" }) {
+      expected.add(name);
+    }
+    assertEquals(expected, config.declinedEngineNames);
+
+    config.declinedEngineNames = null;
+    config.persistToPrefs();
+    assertFalse(prefs.contains(SyncConfiguration.PREF_DECLINED_ENGINE_NAMES));
+    config = newSyncConfiguration();
+    assertNull(config.declinedEngineNames);
+  }
+
+  public void testEnabledEngineNames() {
+    SyncConfiguration config = null;
+    SharedPreferences prefs = getPrefs(TEST_PREFS_NAME, 0);
+
+    config = newSyncConfiguration();
+    config.enabledEngineNames = new HashSet<String>();
+    config.enabledEngineNames.add("test1");
+    config.enabledEngineNames.add("test2");
+    config.persistToPrefs();
+    assertTrue(prefs.contains(SyncConfiguration.PREF_ENABLED_ENGINE_NAMES));
+    config = newSyncConfiguration();
+    Set<String> expected = new HashSet<String>();
+    for (String name : new String[] { "test1", "test2" }) {
+      expected.add(name);
+    }
+    assertEquals(expected, config.enabledEngineNames);
+
+    config.enabledEngineNames = null;
+    config.persistToPrefs();
+    assertFalse(prefs.contains(SyncConfiguration.PREF_ENABLED_ENGINE_NAMES));
+    config = newSyncConfiguration();
+    assertNull(config.enabledEngineNames);
+  }
+
+  public void testSyncID() {
+    SyncConfiguration config = null;
+    SharedPreferences prefs = getPrefs(TEST_PREFS_NAME, 0);
+
+    config = newSyncConfiguration();
+    config.syncID = "test1";
+    config.persistToPrefs();
+    assertTrue(prefs.contains(SyncConfiguration.PREF_SYNC_ID));
+    config = newSyncConfiguration();
+    assertEquals("test1", config.syncID);
+  }
+
+  public void testStoreSelectedEnginesToPrefs() {
+    SharedPreferences prefs = getPrefs(TEST_PREFS_NAME, 0);
+    // Store engines, excluding history/forms special case.
+    Map<String, Boolean> expectedEngines = new HashMap<String, Boolean>();
+    expectedEngines.put("test1", true);
+    expectedEngines.put("test2", false);
+    expectedEngines.put("test3", true);
+
+    SyncConfiguration.storeSelectedEnginesToPrefs(prefs, expectedEngines);
+
+    // Read values from selectedEngines.
+    assertTrue(prefs.contains(SyncConfiguration.PREF_USER_SELECTED_ENGINES_TO_SYNC));
+    SyncConfiguration config = null;
+    config = newSyncConfiguration();
+    config.loadFromPrefs(prefs);
+    assertEquals(expectedEngines, config.userSelectedEngines);
+  }
+
+  /**
+   * Tests dependency of forms engine on history engine.
+   */
+  public void testSelectedEnginesHistoryAndForms() {
+    SharedPreferences prefs = getPrefs(TEST_PREFS_NAME, 0);
+    // Store engines, excluding history/forms special case.
+    Map<String, Boolean> storedEngines = new HashMap<String, Boolean>();
+    storedEngines.put("history", true);
+
+    SyncConfiguration.storeSelectedEnginesToPrefs(prefs, storedEngines);
+
+    // Expected engines.
+    storedEngines.put("forms", true);
+    // Read values from selectedEngines.
+    assertTrue(prefs.contains(SyncConfiguration.PREF_USER_SELECTED_ENGINES_TO_SYNC));
+    SyncConfiguration config = null;
+    config = newSyncConfiguration();
+    config.loadFromPrefs(prefs);
+    assertEquals(storedEngines, config.userSelectedEngines);
+  }
+
+  public void testsSelectedEnginesNoHistoryNorForms() {
+    SharedPreferences prefs = getPrefs(TEST_PREFS_NAME, 0);
+    // Store engines, excluding history/forms special case.
+    Map<String, Boolean> storedEngines = new HashMap<String, Boolean>();
+    storedEngines.put("forms", true);
+
+    SyncConfiguration.storeSelectedEnginesToPrefs(prefs, storedEngines);
+
+    // Read values from selectedEngines.
+    assertTrue(prefs.contains(SyncConfiguration.PREF_USER_SELECTED_ENGINES_TO_SYNC));
+    SyncConfiguration config = null;
+    config = newSyncConfiguration();
+    config.loadFromPrefs(prefs);
+    // Forms should not be selected if history is not present.
+    assertTrue(config.userSelectedEngines.isEmpty());
+  }
+
+  protected SyncConfiguration newSyncConfiguration() {
+    return new SyncConfiguration(null, null, getPrefs(TEST_PREFS_NAME, 0));
+  }
+}