Android: Replace webrtc_jni namespace with nested jni namespace

webrtc/sdk/android/src/jni/pc/video_jni.h

 /*
  *  Copyright 2017 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_SDK_ANDROID_SRC_JNI_PC_VIDEO_JNI_H_
 #define WEBRTC_SDK_ANDROID_SRC_JNI_PC_VIDEO_JNI_H_
 
 #include <jni.h>
 
 #include "webrtc/rtc_base/scoped_ref_ptr.h"
 
 namespace cricket {
 class WebRtcVideoEncoderFactory;
 class WebRtcVideoDecoderFactory;
 }  // namespace cricket
 
-namespace webrtc_jni {
+namespace webrtc {
+namespace jni {
 
 class SurfaceTextureHelper;
 
 cricket::WebRtcVideoEncoderFactory* CreateVideoEncoderFactory(
     JNIEnv* jni,
     jobject j_encoder_factory);
 
 cricket::WebRtcVideoDecoderFactory* CreateVideoDecoderFactory(
     JNIEnv* jni,
     jobject j_decoder_factory);
 
 jobject GetJavaSurfaceTextureHelper(
     const rtc::scoped_refptr<SurfaceTextureHelper>& surface_texture_helper);
 
-}  // namespace webrtc_jni
+}  // namespace jni
+}  // namespace webrtc
 
 #endif  // WEBRTC_SDK_ANDROID_SRC_JNI_PC_VIDEO_JNI_H_