Revert of Move RtcEventLog object from inside VoiceEngine to Call.

webrtc/call/rtc_event_log.h

 /*
  *  Copyright (c) 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.
  */
 
@@ skipping 22 matching lines @@
 
 enum PacketDirection { kIncomingPacket = 0, kOutgoingPacket };
 
 class RtcEventLog {
  public:
   virtual ~RtcEventLog() {}
 
   // Factory method to create an RtcEventLog object.
   static std::unique_ptr<RtcEventLog> Create(const Clock* clock);
 
-  // Create an RtcEventLog object that does nothing.
-  static std::unique_ptr<RtcEventLog> CreateNull();
-
   // Starts logging a maximum of max_size_bytes bytes to the specified file.
   // If the file already exists it will be overwritten.
   // If max_size_bytes <= 0, logging will be active until StopLogging is called.
   // The function has no effect and returns false if we can't start a new log
   // e.g. because we are already logging or the file cannot be opened.
   virtual bool StartLogging(const std::string& file_name,
                             int64_t max_size_bytes) = 0;
 
   // Same as above. The RtcEventLog takes ownership of the file if the call
   // is successful, i.e. if it returns true.
@@ skipping 49 matching lines @@
   // configurations, then the remaining events in timestamp order and finally
   // a LOG_END event. However, this might change without further notice.
   // TODO(terelius): Change result type to a vector?
   static bool ParseRtcEventLog(const std::string& file_name,
                                rtclog::EventStream* result);
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_CALL_RTC_EVENT_LOG_H_