[Tracing] Update sync_id to be string type for clock sync

content/browser/tracing/tracing_controller_impl.h

 // Copyright (c) 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.
 
 #ifndef CONTENT_BROWSER_TRACING_TRACING_CONTROLLER_IMPL_H_
 #define CONTENT_BROWSER_TRACING_TRACING_CONTROLLER_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 52 matching lines @@
   void UnregisterTracingUI(TracingUI* tracing_ui);
 
   // base::trace_event::TracingAgent implementation.
   std::string GetTracingAgentName() override;
   std::string GetTraceEventLabel() override;
   void StartAgentTracing(const base::trace_event::TraceConfig& trace_config,
                          const StartAgentTracingCallback& callback) override;
   void StopAgentTracing(const StopAgentTracingCallback& callback) override;
   bool SupportsExplicitClockSync() override;
   void RecordClockSyncMarker(
-      int sync_id,
+      const std::string& sync_id,
       const RecordClockSyncMarkerCallback& callback) override;
 
   // base::trace_event::MemoryDumpManagerDelegate implementation.
   void RequestGlobalMemoryDump(
       const base::trace_event::MemoryDumpRequestArgs& args,
       const base::trace_event::MemoryDumpCallback& callback) override;
   uint64_t GetTracingProcessId() const override;
 
   class TraceMessageFilterObserver {
    public:
@@ skipping 91 matching lines @@
   void OnAllTracingAgentsStarted();
   void StopTracingAfterClockSync();
   void OnStopTracingDone();
   void OnStartMonitoringDone(
       const base::trace_event::TraceConfig& trace_config,
       const StartMonitoringDoneCallback& callback);
   void OnStopMonitoringDone(const StopMonitoringDoneCallback& callback);
 
   void OnMonitoringStateChanged(bool is_monitoring);
 
-  int GetUniqueClockSyncID();
   // Issue clock sync markers to the tracing agents.
   void IssueClockSyncMarker();
   void OnClockSyncMarkerRecordedByAgent(
-      int sync_id,
+      const std::string& sync_id,
       const base::TimeTicks& issue_ts,
       const base::TimeTicks& issue_end_ts);
 
   typedef std::set<scoped_refptr<TraceMessageFilter>> TraceMessageFilterSet;
   TraceMessageFilterSet trace_message_filters_;
 
   // Pending acks for StartTracing.
   int pending_start_tracing_ack_count_;
   base::OneShotTimer start_tracing_timer_;
   StartTracingDoneCallback start_tracing_done_callback_;
@@ skipping 42 matching lines @@
   std::set<TracingUI*> tracing_uis_;
   scoped_refptr<TraceDataSink> trace_data_sink_;
   scoped_refptr<TraceDataSink> monitoring_data_sink_;
 
   DISALLOW_COPY_AND_ASSIGN(TracingControllerImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_TRACING_TRACING_CONTROLLER_IMPL_H_