Remove redundant field initialization in Java code.

components/policy/android/java/src/org/chromium/policy/CombinedPolicyProvider.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.policy;
 
 import android.os.Bundle;
 
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
 
 import java.util.ArrayList;
 import java.util.List;
 
 /**
  * Reads enterprise policies from one or more policy providers and plumbs them through to the policy
  * subsystem.
  */
 @JNINamespace("policy::android")
 public class CombinedPolicyProvider {
-    private static CombinedPolicyProvider sInstance = null;
+    private static CombinedPolicyProvider sInstance;
 
-    private long mNativeCombinedPolicyProvider = 0;
+    private long mNativeCombinedPolicyProvider;
 
     private PolicyConverter mPolicyConverter;
     private final List<PolicyProvider> mPolicyProviders = new ArrayList<>();
     private final List<Bundle> mCachedPolicies = new ArrayList<>();
     private final List<PolicyChangeListener> mPolicyChangeListeners = new ArrayList<>();
 
     public static CombinedPolicyProvider get() {
         if (sInstance == null) {
             sInstance = new CombinedPolicyProvider();
         }
@@ skipping 100 matching lines @@
     public static void set(CombinedPolicyProvider p) {
         sInstance = p;
     }
 
     @VisibleForTesting
     CombinedPolicyProvider() {}
 
     @VisibleForTesting
     protected native void nativeFlushPolicies(long nativeAndroidCombinedPolicyProvider);
 }