Android: Replace webrtc_jni namespace with nested jni namespace

webrtc/sdk/android/src/jni/pc/datachannelobserver_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_DATACHANNELOBSERVER_JNI_H_
 #define WEBRTC_SDK_ANDROID_SRC_JNI_PC_DATACHANNELOBSERVER_JNI_H_
 
 #include "webrtc/api/datachannelinterface.h"
 #include "webrtc/sdk/android/src/jni/jni_helpers.h"
 
-namespace webrtc_jni {
+namespace webrtc {
+namespace jni {
 
 // Adapter for a Java DataChannel$Observer presenting a C++ DataChannelObserver
 // and dispatching the callback from C++ back to Java.
-class DataChannelObserverJni : public webrtc::DataChannelObserver {
+class DataChannelObserverJni : public DataChannelObserver {
  public:
   DataChannelObserverJni(JNIEnv* jni, jobject j_observer);
   virtual ~DataChannelObserverJni() {}
 
   void OnBufferedAmountChange(uint64_t previous_amount) override;
   void OnStateChange() override;
-  void OnMessage(const webrtc::DataBuffer& buffer) override;
+  void OnMessage(const DataBuffer& buffer) override;
 
  private:
   const ScopedGlobalRef<jobject> j_observer_global_;
   const ScopedGlobalRef<jclass> j_observer_class_;
   const ScopedGlobalRef<jclass> j_buffer_class_;
   const jmethodID j_on_buffered_amount_change_mid_;
   const jmethodID j_on_state_change_mid_;
   const jmethodID j_on_message_mid_;
   const jmethodID j_buffer_ctor_;
 };
 
-}  // namespace webrtc_jni
+}  // namespace jni
+}  // namespace webrtc
 
 #endif  // WEBRTC_SDK_ANDROID_SRC_JNI_PC_DATACHANNELOBSERVER_JNI_H_