Android: Replace webrtc_jni namespace with nested jni namespace

webrtc/sdk/android/src/jni/classreferenceholder.cc

 /*
  *  Copyright 2015 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.
  */
 #include "webrtc/sdk/android/src/jni/classreferenceholder.h"
 
 #include "webrtc/sdk/android/src/jni/jni_helpers.h"
 
-namespace webrtc_jni {
+namespace webrtc {
+namespace jni {
 
 // ClassReferenceHolder holds global reference to Java classes in app/webrtc.
 class ClassReferenceHolder {
  public:
   explicit ClassReferenceHolder(JNIEnv* jni);
   ~ClassReferenceHolder();
 
   void FreeReferences(JNIEnv* jni);
   jclass GetClass(const std::string& name);
 
@@ skipping 121 matching lines @@
   bool inserted = classes_.insert(std::make_pair(name, globalRef)).second;
   RTC_CHECK(inserted) << "Duplicate class name: " << name;
 }
 
 // Returns a global reference guaranteed to be valid for the lifetime of the
 // process.
 jclass FindClass(JNIEnv* jni, const char* name) {
   return g_class_reference_holder->GetClass(name);
 }
 
-}  // namespace webrtc_jni
+}  // namespace jni
+}  // namespace webrtc