Use GoogleAuthUtil's getToken instead of AccountManager

chrome/android/javatests/AndroidManifest.xml

 <?xml version="1.0" encoding="utf-8"?>
 <!-- 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 name must be unique. -->
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="org.chromium.chrome.tests">
 
     <uses-sdk android:minSdkVersion="16" android:targetSdkVersion="23" />
@@ skipping 12 matching lines @@
             android:authorities="org.chromium.chrome.test.TestContentProvider"
             android:exported="true" />
 
         <provider android:name="org.chromium.chrome.test.partnercustomizations.TestPartnerBrowserCustomizationsProvider"
             android:authorities="org.chromium.chrome.test.partnercustomizations.TestPartnerBrowserCustomizationsProvider"
             android:exported="true" />
         <provider android:name="org.chromium.chrome.test.partnercustomizations.TestPartnerBrowserCustomizationsDelayedProvider"
             android:authorities="org.chromium.chrome.test.partnercustomizations.TestPartnerBrowserCustomizationsDelayedProvider"
             android:exported="true" />
 
-        <activity android:name="org.chromium.sync.test.util.MockGrantCredentialsPermissionActivity"
-            android:exported="true">
-            <intent-filter>
-                <action android:name="android.intent.action.VIEW" />
-                <category android:name="android.intent.category.DEFAULT" />
-            </intent-filter>
-        </activity>
-
         <activity android:name="org.chromium.chrome.browser.customtabs.CustomTabExternalNavigationTest$DummyActivityForSpecialScheme"
             android:exported="true" >
             <intent-filter>
                 <action android:name="android.intent.action.VIEW" />
                 <category android:name="android.intent.category.DEFAULT" />
                 <category android:name="android.intent.category.BROWSABLE" />
                 <data android:host="customtabtest" android:scheme="customtab" />
             </intent-filter>
         </activity>
 
@@ skipping 15 matching lines @@
                 <action android:name="org.chromium.chrome.browser.customtabs.TEST_PENDING_INTENT_SENT" >
                 </action>
             </intent-filter>
         </receiver>
     </application>
 
     <instrumentation android:name="org.chromium.chrome.test.ChromeInstrumentationTestRunner"
         android:targetPackage="{{manifest_package}}"
         android:label="Tests for {{manifest_package}}"/>
 </manifest>