Simplify/Cleanup MediaClient

media/base/media_client.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/base/media_client.h"
 
 #include "base/logging.h"
 
 namespace media {
 
 static MediaClient* g_media_client = nullptr;
 
 void SetMediaClient(MediaClient* media_client) {
   g_media_client = media_client;
 }
 
 MediaClient* GetMediaClient() {
   return g_media_client;
 }
 
-KeySystemInfoForUMA::KeySystemInfoForUMA(
-    const std::string& key_system,
-    const std::string& key_system_name_for_uma)
-    : key_system(key_system),
-      key_system_name_for_uma(key_system_name_for_uma) {}
-
-KeySystemInfoForUMA::~KeySystemInfoForUMA() {
-}
-
 MediaClient::MediaClient() {
 }
 
 MediaClient::~MediaClient() {
 }
 
 }  // namespace media