[Offline pages] Ensuring obtaining GcmNetworkManager in BackgroundScheduler does not throw

chrome/android/junit/src/org/chromium/chrome/browser/offlinepages/BackgroundSchedulerTest.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.chrome.browser.offlinepages;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
@@ skipping 10 matching lines @@
 import org.robolectric.annotation.Config;
 import org.robolectric.internal.ShadowExtractor;
 
 import org.chromium.base.BaseChromiumApplication;
 import org.chromium.base.test.util.Feature;
 
 /**
  * Unit tests for BackgroundScheduler.
  */
 @RunWith(OfflinePageTestRunner.class)
-@Config(manifest = Config.NONE,
-        application = BaseChromiumApplication.class,
-        shadows = {ShadowGcmNetworkManager.class})
+@Config(manifest = Config.NONE, application = BaseChromiumApplication.class,
+        shadows = {ShadowGcmNetworkManager.class, ShadowGoogleApiAvailability.class})
 public class BackgroundSchedulerTest {
     private Context mContext;
     private TriggerConditions mConditions1 = new TriggerConditions(
             true /* power */, 10 /* battery percentage */, false /* unmetered */);
     private ShadowGcmNetworkManager mGcmNetworkManager;
 
     @Before
     public void setUp() throws Exception {
         mContext =  RuntimeEnvironment.application;
         mGcmNetworkManager = (ShadowGcmNetworkManager) ShadowExtractor.extract(
@@ skipping 23 matching lines @@
     public void testUnschedule() {
         assertNull(mGcmNetworkManager.getScheduledTask());
         BackgroundScheduler.schedule(mContext, mConditions1);
         assertNotNull(mGcmNetworkManager.getScheduledTask());
 
         assertNull(mGcmNetworkManager.getCanceledTask());
         BackgroundScheduler.unschedule(mContext);
         assertNotNull(mGcmNetworkManager.getCanceledTask());
     }
 }