Fix the timestamp generation for webrtc native log.

chrome/common/media/webrtc_logging_messages.h

 // Copyright 2013 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.
 
 // IPC messages for WebRTC logging.
 // Multiply-included message file, hence no include guard.
 
 #include <string>
 
 #include "base/memory/shared_memory.h"
 #include "ipc/ipc_message_macros.h"
 
 #define IPC_MESSAGE_START WebRtcLoggingMsgStart
 
+IPC_STRUCT_BEGIN(WebRtcLoggingMessage)
+  IPC_STRUCT_MEMBER(uint64, timestamp_ms)
+  IPC_STRUCT_MEMBER(std::string, message)
+IPC_STRUCT_END()
+
 // Messages sent from the renderer to the browser.
 
 // Send log message to add to log.
-IPC_MESSAGE_CONTROL1(WebRtcLoggingMsg_AddLogMessage,
-                     std::string /* message */)
+IPC_MESSAGE_CONTROL1(WebRtcLoggingMsg_AddLogMessages,
+                     std::vector<WebRtcLoggingMessage> /* messages */)
 
 // Notification that the renderer has stopped sending log messages to the
 // browser.
 IPC_MESSAGE_CONTROL0(WebRtcLoggingMsg_LoggingStopped)
 
 // Messages sent from the browser to the renderer.
 
 // Tells the renderer to start sending log messages to the browser.
 IPC_MESSAGE_CONTROL0(WebRtcLoggingMsg_StartLogging)
 
 // Tells the renderer to stop sending log messages to the browser.
 IPC_MESSAGE_CONTROL0(WebRtcLoggingMsg_StopLogging)