Remove redundant field initialization in Java code.

chrome/android/java/src/org/chromium/chrome/browser/superviseduser/SupervisedUserContentProvider.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.superviseduser;
 
 import android.annotation.TargetApi;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
@@ skipping 15 matching lines @@
 import java.util.concurrent.ArrayBlockingQueue;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.TimeUnit;
 
 /**
  * Content provider for telling other apps (e.g. WebView apps) about the supervised user URL filter.
  */
 public class SupervisedUserContentProvider extends WebRestrictionsContentProvider {
     private static final String SUPERVISED_USER_CONTENT_PROVIDER_ENABLED =
             "SupervisedUserContentProviderEnabled";
-    private long mNativeSupervisedUserContentProvider = 0;
+    private long mNativeSupervisedUserContentProvider;
     private boolean mChromeAlreadyStarted;
     private static Object sEnabledLock = new Object();
 
     // Three value "boolean" caching enabled state, null if not yet known.
-    private static Boolean sEnabled = null;
+    private static Boolean sEnabled;
 
     private long getSupervisedUserContentProvider() throws ProcessInitException {
         mChromeAlreadyStarted = LibraryLoader.isInitialized();
         if (mNativeSupervisedUserContentProvider != 0) {
             return mNativeSupervisedUserContentProvider;
         }
 
         ChromeBrowserInitializer.getInstance(getContext()).handleSynchronousStartup();
 
         mNativeSupervisedUserContentProvider = nativeCreateSupervisedUserContentProvider();
@@ skipping 215 matching lines @@
     private native void nativeSetFilterForTesting(long nativeSupervisedUserContentProvider);
 
     @Override
     protected String[] getErrorColumnNames() {
         String result[] = {"Reason", "Allow access requests", "Is child account",
                 "Profile image URL", "Second profile image URL", "Custodian", "Custodian email",
                 "Second custodian", "Second custodian email"};
         return result;
     }
 }