Android JNI gen: Don't emit code for empty RegisterNatives()

chromecast/base/cast_sys_info_android.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 CHROMECAST_BASE_CAST_SYS_INFO_ANDROID_H_
 #define CHROMECAST_BASE_CAST_SYS_INFO_ANDROID_H_
 
 #include <jni.h>
 
 #include "base/macros.h"
 #include "chromecast/public/cast_sys_info.h"
 
 namespace base {
 namespace android {
 class BuildInfo;
 }
 }
 
 namespace chromecast {
 
 class CastSysInfoAndroid : public CastSysInfo {
  public:
-  static bool RegisterJni(JNIEnv* env);
-
   CastSysInfoAndroid();
   ~CastSysInfoAndroid() override;
 
   // CastSysInfo implementation:
   BuildType GetBuildType() override;
   std::string GetSerialNumber() override;
   std::string GetProductName() override;
   std::string GetDeviceModel() override;
   std::string GetManufacturer() override;
   std::string GetSystemBuildNumber() override;
   std::string GetSystemReleaseChannel() override;
   std::string GetBoardName() override;
   std::string GetBoardRevision() override;
   std::string GetFactoryCountry() override;
   std::string GetFactoryLocale(std::string* second_locale) override;
   std::string GetWifiInterface() override;
   std::string GetApInterface() override;
   std::string GetGlVendor() override;
   std::string GetGlRenderer() override;
   std::string GetGlVersion() override;
 
-  // Native implementation of Java methods.
-  void DeviceNameChanged(JNIEnv* env, jobject obj, jstring device_name);
-
  private:
   const base::android::BuildInfo* const build_info_;
 
   DISALLOW_COPY_AND_ASSIGN(CastSysInfoAndroid);
 };
 
 }  // namespace chromecast
 
 #endif  // CHROMECAST_BASE_CAST_SYS_INFO_ANDROID_H_