Remove redundant field initialization in Java code.

chrome/android/java/src/org/chromium/chrome/browser/omaha/OmahaClient.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.omaha;
 
 import android.app.AlarmManager;
 import android.app.IntentService;
 import android.app.PendingIntent;
 import android.content.Context;
@@ skipping 92 matching lines @@
     @VisibleForTesting
     static final String PREF_MARKET_URL = "marketURL";
 
     private static final long INVALID_TIMESTAMP = -1;
     @VisibleForTesting
     static final String INVALID_REQUEST_ID = "invalid";
 
     // Static fields
     private static boolean sEnableCommunication = true;
     private static boolean sEnableUpdateDetection = true;
-    private static VersionNumberGetter sVersionNumberGetter = null;
-    private static MarketURLGetter sMarketURLGetter = null;
-    private static Boolean sIsFreshInstallOrDataCleared = null;
+    private static VersionNumberGetter sVersionNumberGetter;
+    private static MarketURLGetter sMarketURLGetter;
+    private static Boolean sIsFreshInstallOrDataCleared;
 
     // Member fields not persisted to disk.
     private boolean mStateHasBeenRestored;
     private ExponentialBackoffScheduler mBackoffScheduler;
     private RequestGenerator mGenerator;
 
     // State saved written to and read from disk.
     private RequestData mCurrentRequest;
     private long mTimestampOfInstall;
     private long mTimestampForNextPostAttempt;
@@ skipping 706 matching lines @@
     }
 
     protected final ExponentialBackoffScheduler getBackoffScheduler() {
         if (mBackoffScheduler == null) {
             mBackoffScheduler = createBackoffScheduler(
                     PREF_PACKAGE, this, MS_POST_BASE_DELAY, MS_POST_MAX_DELAY);
         }
         return mBackoffScheduler;
     }
 }