Update Android instrumentation tests to use JUnit4.

webrtc/sdk/android/instrumentationtests/src/org/webrtc/WebRtcJniBootTest.java

 /*
  *  Copyright 2016 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 package org.appspot.apprtc.test;
 
-import android.test.InstrumentationTestCase;
-import android.test.suitebuilder.annotation.SmallTest;
-
+import android.support.test.InstrumentationRegistry;
+import android.support.test.filters.SmallTest;
+import org.chromium.base.test.BaseJUnit4ClassRunner;
+import org.junit.Test;
+import org.junit.runner.RunWith;
 import org.webrtc.PeerConnectionFactory;
 
 // This test is intended to run on ARM and catch LoadLibrary errors when we load the WebRTC
 // JNI. It can't really be setting up calls since ARM emulators are too slow, but instantiating
 // a peer connection isn't timing-sensitive, so we can at least do that.
-public class WebRtcJniBootTest extends InstrumentationTestCase {
+@RunWith(BaseJUnit4ClassRunner.class)
+public class WebRtcJniBootTest {
+  @Test
   @SmallTest
   public void testJniLoadsWithoutError() throws InterruptedException {
-    PeerConnectionFactory.initializeAndroidGlobals(getInstrumentation().getTargetContext(),
+    PeerConnectionFactory.initializeAndroidGlobals(InstrumentationRegistry.getTargetContext(),
         true /* initializeAudio */, true /* initializeVideo */,
         false /* videoCodecHwAcceleration */);
 
     PeerConnectionFactory.Options options = new PeerConnectionFactory.Options();
     new PeerConnectionFactory(options);
   }
 }