Change AccountManagerHelper initialization

chrome/android/javatests/src/org/chromium/chrome/browser/signin/SigninHelperTest.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.signin;
 
 import android.accounts.Account;
 import android.support.test.InstrumentationRegistry;
 import android.support.test.filters.SmallTest;
 
-import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
 import org.chromium.base.test.util.AdvancedMockContext;
 import org.chromium.base.test.util.DisabledTest;
 import org.chromium.base.test.util.RetryOnFailure;
 import org.chromium.chrome.test.ChromeJUnit4ClassRunner;
 import org.chromium.chrome.test.util.browser.signin.MockChangeEventChecker;
@@ skipping 10 matching lines @@
     private FakeAccountManagerDelegate mAccountManager;
     private AdvancedMockContext mContext;
     private MockChangeEventChecker mEventChecker;
 
     @Before
     public void setUp() {
         mContext = new AdvancedMockContext(
                 InstrumentationRegistry.getInstrumentation().getTargetContext());
         mEventChecker = new MockChangeEventChecker();
 
-        mAccountManager = new FakeAccountManagerDelegate(mContext);
-        AccountManagerHelper.overrideAccountManagerHelperForTests(mContext, mAccountManager);
-    }
-
-    @After
-    public void tearDown() {
-        AccountManagerHelper.resetAccountManagerHelperForTests();
+        mAccountManager = new FakeAccountManagerDelegate();
+        AccountManagerHelper.overrideAccountManagerHelperForTests(mAccountManager);
     }
 
     @Test
     @SmallTest
     @RetryOnFailure
     public void testAccountsChangedPref() {
         Assert.assertEquals("Should never return true before the pref has ever been set.", false,
                 SigninHelper.checkAndClearAccountsChangedPref(mContext));
         Assert.assertEquals("Should never return true before the pref has ever been set.", false,
                 SigninHelper.checkAndClearAccountsChangedPref(mContext));
@@ skipping 99 matching lines @@
     }
 
     private String getSignedInAccountName() {
         return ChromeSigninController.get().getSignedInAccountName();
     }
 
     private String getNewSignedInAccountName() {
         return SigninHelper.getNewSignedInAccountName(mContext);
     }
 }