Revert of Loosening the coupling between WebRTC and //third_party/protobuf

webrtc/modules/audio_coding/audio_network_adaptor/debug_dump_writer.h

 /*
  *  Copyright (c) 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.
  */
 
 #ifndef WEBRTC_MODULES_AUDIO_CODING_AUDIO_NETWORK_ADAPTOR_DEBUG_DUMP_WRITER_H_
 #define WEBRTC_MODULES_AUDIO_CODING_AUDIO_NETWORK_ADAPTOR_DEBUG_DUMP_WRITER_H_
 
 #include <memory>
+#include <string>
 
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/modules/audio_coding/audio_network_adaptor/controller.h"
 #include "webrtc/modules/audio_coding/audio_network_adaptor/include/audio_network_adaptor.h"
 #include "webrtc/system_wrappers/include/file_wrapper.h"
 
 namespace webrtc {
 
 class DebugDumpWriter {
  public:
   static std::unique_ptr<DebugDumpWriter> Create(FILE* file_handle);
 
   virtual ~DebugDumpWriter() = default;
 
   virtual void DumpEncoderRuntimeConfig(
       const AudioNetworkAdaptor::EncoderRuntimeConfig& config,
       int64_t timestamp) = 0;
 
   virtual void DumpNetworkMetrics(const Controller::NetworkMetrics& metrics,
                                   int64_t timestamp) = 0;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_CODING_AUDIO_NETWORK_ADAPTOR_DEBUG_DUMP_WRITER_H_