Remove redundant field initialization in Java code.

components/gcm_driver/instance_id/android/javatests/src/org/chromium/components/gcm_driver/instance_id/FakeInstanceIDWithSubtype.java

 // Copyright 2016 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.components.gcm_driver.instance_id;
 
 import android.content.Context;
 import android.os.Bundle;
 import android.os.Looper;
 import android.util.Pair;
 
 import com.google.android.gms.iid.InstanceID;
 
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
 
 import java.io.IOException;
 
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Random;
 
 /**
  * Fake for InstanceIDWithSubtype. Doesn't hit the network or filesystem (so instance IDs don't
  * survive restarts, and sending messages to tokens via the GCM server won't work).
  */
 @JNINamespace("instance_id")
 public class FakeInstanceIDWithSubtype extends InstanceIDWithSubtype {
-    private String mId = null;
-    private long mCreationTime = 0;
+    private String mId;
+    private long mCreationTime;
 
     /** Map from (subtype + ',' + authorizedEntity + ',' + scope) to token. */
     private Map<String, String> mTokens = new HashMap<>();
 
     /**
      * Enable this in all InstanceID tests to use this fake instead of hitting the network/disk.
      * @return The previous value.
      */
     @CalledByNative
     public static boolean clearDataAndSetEnabled(boolean enable) {
@@ skipping 134 matching lines @@
                 "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-_";
         Random random = new Random();
         StringBuilder sb = new StringBuilder(encodedLength);
         for (int i = 0; i < encodedLength; i++) {
             int index = random.nextInt(base64urlAlphabet.length());
             sb.append(base64urlAlphabet.charAt(index));
         }
         return sb.toString();
     }
 }