Revert of [Android] Update all Robolectric tests to Robolectric 3.0

testing/android/junit/java/src/org/chromium/testing/local/BackgroundShadowAsyncTask.java

 // Copyright 2015 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.testing.local;
 
 import static org.junit.Assert.fail;
 
 import android.os.AsyncTask;
 
+import org.robolectric.Robolectric;
 import org.robolectric.annotation.Implementation;
 import org.robolectric.annotation.Implements;
-import org.robolectric.shadows.ShadowApplication;
 import org.robolectric.shadows.ShadowAsyncTask;
 
 import java.util.concurrent.Callable;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 
 /**
  * Executes async tasks on a background thread and waits on the result on the main thread.
  * This is useful for users of AsyncTask on Roboelectric who check if the code is actually being
  * run on a background thread (i.e. through the use of {@link ThreadUtils#runningOnUiThread()}).
@@ skipping 20 matching lines @@
         } catch (Exception ex) {
             fail(ex.getMessage());
             return null;
         }
     }
 
     public static void runBackgroundTasks() throws Exception {
         sExecutorService.submit(new Runnable() {
             @Override
             public void run() {
-                ShadowApplication.runBackgroundTasks();
+                Robolectric.runBackgroundTasks();
             }
         }).get();
     }
-}
+}