Android: Replace webrtc_jni namespace with nested jni namespace

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

 /*
  *  Copyright 2016 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 <map>
 #include <memory>
 
 #include "webrtc/sdk/android/src/jni/classreferenceholder.h"
 #include "webrtc/sdk/android/src/jni/jni_helpers.h"
 #include "webrtc/system_wrappers/include/metrics.h"
 
 // Enables collection of native histograms and creating them.
-namespace webrtc_jni {
+namespace webrtc {
+namespace jni {
 
 JNI_FUNCTION_DECLARATION(jlong,
                          Histogram_nativeCreateCounts,
                          JNIEnv* jni,
                          jclass,
                          jstring j_name,
                          jint min,
                          jint max,
                          jint buckets) {
   std::string name = JavaToStdString(jni, j_name);
   return jlongFromPointer(
-      webrtc::metrics::HistogramFactoryGetCounts(name, min, max, buckets));
+      metrics::HistogramFactoryGetCounts(name, min, max, buckets));
 }
 
 JNI_FUNCTION_DECLARATION(jlong,
                          Histogram_nativeCreateEnumeration,
                          JNIEnv* jni,
                          jclass,
                          jstring j_name,
                          jint max) {
   std::string name = JavaToStdString(jni, j_name);
-  return jlongFromPointer(
-      webrtc::metrics::HistogramFactoryGetEnumeration(name, max));
+  return jlongFromPointer(metrics::HistogramFactoryGetEnumeration(name, max));
 }
 
 JNI_FUNCTION_DECLARATION(void,
                          Histogram_nativeAddSample,
                          JNIEnv* jni,
                          jclass,
                          jlong histogram,
                          jint sample) {
   if (histogram) {
-    HistogramAdd(reinterpret_cast<webrtc::metrics::Histogram*>(histogram),
-                 sample);
+    HistogramAdd(reinterpret_cast<metrics::Histogram*>(histogram), sample);
   }
 }
 
-}  // namespace webrtc_jni
+}  // namespace jni
+}  // namespace webrtc