Android: Replace webrtc_jni namespace with nested jni namespace

webrtc/sdk/android/src/jni/pc/mediaconstraints_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_MEDIACONSTRAINTS_JNI_H_
 #define WEBRTC_SDK_ANDROID_SRC_JNI_PC_MEDIACONSTRAINTS_JNI_H_
 
 #include "webrtc/api/mediaconstraintsinterface.h"
 #include "webrtc/sdk/android/src/jni/jni_helpers.h"
 
-namespace webrtc_jni {
+namespace webrtc {
+namespace jni {
 
 // Wrapper for a Java MediaConstraints object.  Copies all needed data so when
 // the constructor returns the Java object is no longer needed.
-class MediaConstraintsJni : public webrtc::MediaConstraintsInterface {
+class MediaConstraintsJni : public MediaConstraintsInterface {
  public:
   MediaConstraintsJni(JNIEnv* jni, jobject j_constraints);
   virtual ~MediaConstraintsJni() {}
 
   // MediaConstraintsInterface.
   const Constraints& GetMandatory() const override { return mandatory_; }
   const Constraints& GetOptional() const override { return optional_; }
 
  private:
   // Helper for translating a List<Pair<String, String>> to a Constraints.
   static void PopulateConstraintsFromJavaPairList(JNIEnv* jni,
                                                   jobject j_constraints,
                                                   const char* field_name,
                                                   Constraints* field);
 
   Constraints mandatory_;
   Constraints optional_;
 };
 
-}  // namespace webrtc_jni
+}  // namespace jni
+}  // namespace webrtc
 
 #endif  // WEBRTC_SDK_ANDROID_SRC_JNI_PC_MEDIACONSTRAINTS_JNI_H_