Remove redundant field initialization in Java code.

android_webview/java/src/org/chromium/android_webview/AwContentsLifecycleNotifier.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.android_webview;
 
 import org.chromium.base.ObserverList;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
@@ skipping 10 matching lines @@
     /**
      * Observer interface to be implemented by deriving webview lifecycle observers.
      */
     public static interface Observer {
         public void onFirstWebViewCreated();
         public void onLastWebViewDestroyed();
     }
 
     private static final ObserverList<Observer> sLifecycleObservers =
             new ObserverList<Observer>();
-    private static int sNumWebViews = 0;
+    private static int sNumWebViews;
 
     private AwContentsLifecycleNotifier() {}
 
     public static void addObserver(Observer observer) {
         sLifecycleObservers.addObserver(observer);
     }
 
     public static void removeObserver(Observer observer) {
         sLifecycleObservers.removeObserver(observer);
     }
@@ skipping 23 matching lines @@
         assert sNumWebViews > 0;
         sNumWebViews--;
         if (sNumWebViews == 0) {
             // last webview destroyed, notify observers.
             for (Observer observer : sLifecycleObservers) {
                 observer.onLastWebViewDestroyed();
             }
         }
     }
 }