Convert rtc_event_log from webrtc::Clock to rtc::TimeMicros.

webrtc/logging/rtc_event_log/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 class MediaType;
 
 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);
+  static std::unique_ptr<RtcEventLog> Create();
+  // TODO(nisse): webrtc::Clock is deprecated. Delete this method and
+  // above forward declaration of Clock when
+  // webrtc/system_wrappers/include/clock.h is deleted.
+  static std::unique_ptr<RtcEventLog> Create(const Clock* clock) {
+    return Create();
+  }
 
   // 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,
@@ skipping 93 matching lines @@
                      size_t length) override {}
   void LogAudioPlayout(uint32_t ssrc) override {}
   void LogBwePacketLossEvent(int32_t bitrate,
                              uint8_t fraction_loss,
                              int32_t total_packets) override {}
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_LOGGING_RTC_EVENT_LOG_RTC_EVENT_LOG_H_