--- a/mobile/android/base/java/org/mozilla/gecko/SharedPreferencesHelper.java
+++ b/mobile/android/base/java/org/mozilla/gecko/SharedPreferencesHelper.java
@@ -12,16 +12,18 @@ import org.mozilla.gecko.util.GeckoBundl
 
 import android.content.Context;
 import android.content.SharedPreferences;
 import android.preference.PreferenceManager;
 import android.util.Log;
 
 import java.util.Map;
 import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Arrays;
 
 /**
  * Helper class to get, set, and observe Android Shared Preferences.
  */
 public final class SharedPreferencesHelper
              implements BundleEventListener
 {
     public static final String LOGTAG = "GeckoAndSharedPrefs";
@@ -118,17 +120,17 @@ public final class SharedPreferencesHelp
     }
 
     /**
      * Set many SharedPreferences in Android.
      *
      * message.branch must exist, and should be a String SharedPreferences
      * branch name, or null for the default branch.
      * message.preferences should be an array of preferences.  Each preference
-     * must include a String name, a String type in ["bool", "int", "string"],
+     * must include a String name, a String type in ["bool", "int", "string", "set"],
      * and an Object value.
      */
     private void handleSet(final GeckoBundle message) {
         SharedPreferences.Editor editor = getSharedPreferences(message).edit();
 
         final GeckoBundle[] bundlePrefs = message.getBundleArray("preferences");
 
         for (int i = 0; i < bundlePrefs.length; i++) {
@@ -136,31 +138,34 @@ public final class SharedPreferencesHelp
             final String name = pref.getString("name");
             final String type = pref.getString("type");
             if ("bool".equals(type)) {
                 editor.putBoolean(name, pref.getBoolean("value"));
             } else if ("int".equals(type)) {
                 editor.putInt(name, pref.getInt("value"));
             } else if ("string".equals(type)) {
                 editor.putString(name, pref.getString("value"));
+            } else if ("set".equals(type)) {
+                HashSet<String> mySet = new HashSet<String>(Arrays.asList(pref.getStringArray("value")));
+                editor.putStringSet(name, mySet);
             } else {
                 Log.w(LOGTAG, "Unknown pref value type [" + type + "] for pref [" + name + "]");
             }
         }
         editor.apply();
     }
 
     /**
      * Get many SharedPreferences from Android.
      *
      * message.branch must exist, and should be a String SharedPreferences
      * branch name, or null for the default branch.
      * message.preferences should be an array of preferences.  Each preference
      * must include a String name, and a String type in ["bool", "int",
-     * "string"].
+     * "string", "set"].
      */
     private GeckoBundle[] handleGet(final GeckoBundle message) {
         final SharedPreferences prefs = getSharedPreferences(message);
         final GeckoBundle[] bundlePrefs = message.getBundleArray("preferences");
         final GeckoBundle[] bundleValues = new GeckoBundle[bundlePrefs.length];
 
         for (int i = 0; i < bundlePrefs.length; i++) {
             final GeckoBundle pref = bundlePrefs[i];
@@ -171,16 +176,18 @@ public final class SharedPreferencesHelp
             bundleValue.putString("type", type);
             try {
                 if ("bool".equals(type)) {
                     bundleValue.putBoolean("value", prefs.getBoolean(name, false));
                 } else if ("int".equals(type)) {
                     bundleValue.putInt("value", prefs.getInt(name, 0));
                 } else if ("string".equals(type)) {
                     bundleValue.putString("value", prefs.getString(name, ""));
+                } else if ("set".equals(type)) {
+                    bundleValue.putStringArray("value", prefs.getStringSet(name, new HashSet<String>()));
                 } else {
                     Log.w(LOGTAG, "Unknown pref value type [" + type + "] for pref [" + name + "]");
                 }
             } catch (final ClassCastException e) {
                 // Thrown if there is a preference with the given name that is
                 // not the right type.
                 Log.w(LOGTAG, "Wrong pref value type [" + type + "] for pref [" + name + "]", e);
             }

--- a/mobile/android/base/java/org/mozilla/gecko/preferences/MultiPrefMultiChoicePreference.java
+++ b/mobile/android/base/java/org/mozilla/gecko/preferences/MultiPrefMultiChoicePreference.java
@@ -49,17 +49,17 @@ class MultiPrefMultiChoicePreference ext
 
     // Overridden to do a one time import for the old preference type to the new one.
     @Override
     protected synchronized void loadPersistedValues() {
         // This will load the new pref if it exists.
         super.loadPersistedValues();
 
         // First check if we've already done the import the old data. If so, nothing to load.
-        final SharedPreferences prefs = GeckoSharedPrefs.forApp(getContext());
+        final SharedPreferences prefs = GeckoSharedPrefs.forProfile(getContext());
         final boolean imported = getPersistedBoolean(prefs, getKey() + IMPORT_SUFFIX, false);
         if (imported) {
             return;
         }
 
         // Load the data we'll need to find the old style prefs
         final CharSequence[] init = getInitialValues();
         final CharSequence[] entries = getEntries();

--- a/mobile/android/modules/SharedPreferences.jsm
+++ b/mobile/android/modules/SharedPreferences.jsm
@@ -98,16 +98,20 @@ SharedPreferencesImpl.prototype = Object
   setBoolPref: function setBoolPref(prefName, value) {
     this._setOne(prefName, value, "bool");
   },
 
   setCharPref: function setCharPref(prefName, value) {
     this._setOne(prefName, value, "string");
   },
 
+  setSetPref: function setCharPref(prefName, value) {
+    this._setOne(prefName, value, "set");
+  },
+
   setIntPref: function setIntPref(prefName, value) {
     this._setOne(prefName, value, "int");
   },
 
   _get: function _get(prefs, callback) {
     let result = null;
 
     // Use dispatch instead of sendRequestForResult because callbacks for
@@ -141,16 +145,20 @@ SharedPreferencesImpl.prototype = Object
   getBoolPref: function getBoolPref(prefName) {
     return this._getOne(prefName, "bool");
   },
 
   getCharPref: function getCharPref(prefName) {
     return this._getOne(prefName, "string");
   },
 
+  getSetPref: function getSetPref(prefName) {
+    return this._getOne(prefName, "set");
+  },
+
   getIntPref: function getIntPref(prefName) {
     return this._getOne(prefName, "int");
   },
 
   /**
    * Invoke `observer` after a change to the preference `domain` in
    * the current branch.
    *