Integrate UI with authentication flow.

blimp/client/core/android/java/src/org/chromium/blimp/core/settings/PreferencesUtil.java

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.blimp.core.settings;
 
 import org.chromium.base.ContextUtils;
 
 /**
  * Blimp preferences utilities.
  */
 public class PreferencesUtil {
-    private static final String DEFAULT_ASSIGNER_URL =
+    /**
+     * Blimp switch preference key, also the key for this PreferenceFragment.
+     */
+    public static final String PREF_BLIMP_SWITCH = "blimp_switch";
+    /**
+     * Blimp assigner URL preference key.
+     */
+    public static final String PREF_ASSIGNER_URL = "blimp_assigner_url";
+
+    /**
+     * Default assigner URL.
+     */
+    public static final String DEFAULT_ASSIGNER_URL =
             "https://dev-blimp-pa.sandbox.googleapis.com/v1/assignment";
 
     /**
      * Reads the last used assigner from shared preference.
      * @return The saved value of assigner preference, or the default development assigner URL
      * if we didn't find the shared preference.
      */
     public static String getLastUsedAssigner() {
         return ContextUtils.getAppSharedPreferences().getString(
-                AboutBlimpPreferences.PREF_ASSIGNER_URL, DEFAULT_ASSIGNER_URL);
+                PREF_ASSIGNER_URL, DEFAULT_ASSIGNER_URL);
+    }
+
+    /**
+     * @return If Blimp switch preference in the setting page is turned on.
+     */
+    public static boolean isBlimpEnabled() {
+        return ContextUtils.getAppSharedPreferences().getBoolean(PREF_BLIMP_SWITCH, false);
     }
 }