android_webview: Remove unneeded RegisterNatives() calls

android_webview/native/aw_contents_lifecycle_notifier.h

 // 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.
 
 #ifndef ANDROID_WEBVIEW_NATIVE_AW_CONTENTS_LIFECYCLE_OBSERVER_H_
 #define ANDROID_WEBVIEW_NATIVE_AW_CONTENTS_LIFECYCLE_OBSERVER_H_
 
 #include "base/android/jni_android.h"
 #include "base/macros.h"
 
 namespace android_webview {
 
 class AwContentsLifecycleNotifier {
  public:
   static void OnWebViewCreated();
   static void OnWebViewDestroyed();
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(AwContentsLifecycleNotifier);
 };
 
-bool RegisterAwContentsLifecycleNotifier(JNIEnv* env);
-
 }  // namespace android_webview
 
 #endif