[Tracing Clock Sync] Implement clock sync in Chrome

base/trace_event/tracing_agent.h

 // Copyright 2015 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.
 
 #ifndef BASE_TRACE_EVENT_TRACING_AGENT_H_
 #define BASE_TRACE_EVENT_TRACING_AGENT_H_
 
 #include "base/base_export.h"
 #include "base/callback.h"
 #include "base/memory/ref_counted_memory.h"
@@ skipping 14 matching lines @@
 // DebugDaemonClient for CrOs system trace, EtwSystemEventConsumer for Windows
 // system trace and PowerTracingAgent for BattOr power trace.
 class BASE_EXPORT TracingAgent {
  public:
   using StopAgentTracingCallback = base::Callback<void(
       const std::string& agent_name,
       const std::string& events_label,
       const scoped_refptr<base::RefCountedString>& events_str_ptr)>;
   using RecordClockSyncMarkerCallback = base::Callback<void(
       int sync_id,
-      const TimeTicks& sync_ts,
-      const TimeTicks& sync_end_ts)>;
+      const TimeTicks& issue_ts,
+      const TimeTicks& issue_end_ts)>;
 
   virtual ~TracingAgent();
 
   // Gets the name of the tracing agent. Each tracing agent's name should be
   // unique.
   virtual std::string GetTracingAgentName() = 0;
 
   // Gets the trace event label of this tracing agent. The label will be used to
   // label this agent's trace when all traces from different tracing agents are
   // combined. Multiple tracing agents could have the same label. The tracing
@@ skipping 36 matching lines @@
   // is true in Chrome because all agent threads' clocks are Chrome clock.
   virtual void RecordClockSyncMarker(
       int sync_id,
       const RecordClockSyncMarkerCallback& callback);
 };
 
 }  // namespace trace_event
 }  // namespace base
 
 #endif  // BASE_TRACE_EVENT_TRACING_AGENT_H_