android_webview: Remove unneeded RegisterNatives() calls

android_webview/native/aw_contents_background_thread_client.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_BACKGROUND_THREAD_CLIENT_H_
 #define ANDROID_WEBVIEW_NATIVE_AW_CONTENTS_BACKGROUND_THREAD_CLIENT_H_
 
 #include "base/android/scoped_java_ref.h"
 
 namespace android_webview {
 
 class AwContentsBackgroundThreadClient {
  public:
   static base::android::ScopedJavaLocalRef<jobject> shouldInterceptRequest(
       JNIEnv* env,
       jobject obj,
       jstring url,
       jboolean isMainFrame,
       jboolean hasUserGesture,
       jstring method,
       jobjectArray requestHeaderNames,
       jobjectArray requestHeaderValues);
 };
 
-// JNI registration method.
-bool RegisterAwContentsBackgroundThreadClient(JNIEnv* env);
-
 }
 
 #endif  // ANDROID_WEBVIEW_NATIVE_AW_CONTENTS_BACKGROUND_THREAD_CLIENT_H_