Remove redundant field initialization in Java code.

chrome/test/android/javatests/src/org/chromium/chrome/test/util/ApplicationTestUtils.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.test.util;
 
 import android.annotation.TargetApi;
 import android.app.Activity;
 import android.app.ActivityManager;
 import android.content.Context;
@@ skipping 16 matching lines @@
 
 import java.util.concurrent.Callable;
 
 /**
  * Methods used for testing Chrome at the Application-level.
  */
 public class ApplicationTestUtils {
     private static final String TAG = "ApplicationTestUtils";
     private static final float FLOAT_EPSILON = 0.001f;
 
-    private static PowerManager.WakeLock sWakeLock = null;
+    private static PowerManager.WakeLock sWakeLock;
 
     // TODO(jbudorick): fix deprecation warning crbug.com/537347
     @SuppressWarnings("deprecation")
     public static void setUp(Context context, boolean clearAppData)
             throws Exception {
         if (clearAppData) {
             // Clear data and remove any tasks listed in Android's Overview menu between test runs.
             clearAppData(context);
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                 finishAllChromeTasks(context);
@@ skipping 167 matching lines @@
                 if (activity.getCurrentContentViewCore() == null) return false;
 
                 updateFailureReason("Expecting scale factor of: " + expectedScale + ", got: "
                         + activity.getCurrentContentViewCore().getScale());
                 return Math.abs(activity.getCurrentContentViewCore().getScale() - expectedScale)
                         < FLOAT_EPSILON;
             }
         }, waitTimeInMs, CriteriaHelper.DEFAULT_POLLING_INTERVAL);
     }
 }