Convert ChromeActivityTestCaseBase direct children to JUnit4

chrome/android/javatests/src/org/chromium/chrome/browser/policy/CombinedPolicyProviderTest.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.chrome.browser.policy;
 
 import android.support.test.filters.SmallTest;
 
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
 import org.chromium.base.ThreadUtils;
+import org.chromium.base.test.util.CommandLineFlags;
 import org.chromium.base.test.util.Feature;
 import org.chromium.base.test.util.RetryOnFailure;
 import org.chromium.chrome.browser.ChromeActivity;
+import org.chromium.chrome.browser.ChromeSwitches;
 import org.chromium.chrome.browser.tabmodel.TabModel;
-import org.chromium.chrome.test.ChromeActivityTestCaseBase;
+import org.chromium.chrome.test.ChromeActivityTestRule;
+import org.chromium.chrome.test.ChromeJUnit4ClassRunner;
 import org.chromium.policy.CombinedPolicyProvider;
 import org.chromium.policy.PolicyProvider;
 
 /** Instrumentation tests for {@link CombinedPolicyProvider} */
-public class CombinedPolicyProviderTest extends ChromeActivityTestCaseBase<ChromeActivity> {
+@RunWith(ChromeJUnit4ClassRunner.class)
+@CommandLineFlags.Add({ChromeSwitches.DISABLE_FIRST_RUN_EXPERIENCE,
+        ChromeActivityTestRule.DISABLE_NETWORK_PREDICTION_FLAG})
+public class CombinedPolicyProviderTest {
+    @Rule
+    public ChromeActivityTestRule<ChromeActivity> mActivityTestRule =
+            new ChromeActivityTestRule<>(ChromeActivity.class);
+
     private static final String DATA_URI = "data:text/plain;charset=utf-8;base64,dGVzdA==";
 
-    public CombinedPolicyProviderTest() {
-        super(ChromeActivity.class);
-    }
-
-    @Override
-    public void startMainActivity() throws InterruptedException {
-        startMainActivityOnBlankPage();
+    @Before
+    public void setUp() throws InterruptedException {
+        mActivityTestRule.startMainActivityOnBlankPage();
     }
 
     /**
      * Checks that the {@link CombinedPolicyProvider} properly notifies tabs when incognito mode is
      * disabled.
      */
-    @Feature({"Policy" })
+    @Test
+    @Feature({"Policy"})
     @SmallTest
     @RetryOnFailure
     public void testTerminateIncognitoSon() throws InterruptedException {
         final boolean incognitoMode = true;
 
-        TabModel incognitoTabModel = getActivity().getTabModelSelector().getModel(incognitoMode);
-        loadUrlInNewTab(DATA_URI, incognitoMode);
-        loadUrlInNewTab(DATA_URI, incognitoMode);
-        assertEquals(2, incognitoTabModel.getCount());
+        TabModel incognitoTabModel =
+                mActivityTestRule.getActivity().getTabModelSelector().getModel(incognitoMode);
+        mActivityTestRule.loadUrlInNewTab(DATA_URI, incognitoMode);
+        mActivityTestRule.loadUrlInNewTab(DATA_URI, incognitoMode);
+        Assert.assertEquals(2, incognitoTabModel.getCount());
 
         final CombinedPolicyProvider provider = CombinedPolicyProvider.get();
         ThreadUtils.runOnUiThreadBlocking(new Runnable() {
             @Override
             public void run() {
                 provider.registerProvider(new PolicyProvider() {
                     @Override
                     public void refresh() {
                         terminateIncognitoSession();
                     }
                 });
             }
         });
 
-        assertEquals(0, incognitoTabModel.getCount());
+        Assert.assertEquals(0, incognitoTabModel.getCount());
     }
 }