[Tracing Clock Sync] Add TracingAgent interface in Chrome

content/browser/tracing/etw_system_event_consumer_win.cc

Index: content/browser/tracing/etw_system_event_consumer_win.cc
diff --git a/content/browser/tracing/etw_system_event_consumer_win.cc b/content/browser/tracing/etw_system_event_consumer_win.cc
index 529800f2202c48f7efce6795e2475e7acf20e0aa..644a56fbb4037119184ff1e7ed6000482da66c6a 100644
--- a/content/browser/tracing/etw_system_event_consumer_win.cc
+++ b/content/browser/tracing/etw_system_event_consumer_win.cc
@@ -36,8 +36,12 @@ EtwSystemEventConsumer::EtwSystemEventConsumer()
 EtwSystemEventConsumer::~EtwSystemEventConsumer() {
 }
 
-bool EtwSystemEventConsumer::StartSystemTracing() {
+std::string EtwSystemEventConsumer::GetTracingAgentName() {
+  return kETWTracingAgentName;
+}
 
+bool EtwSystemEventConsumer::StartAgentTracing(
+    const base::trace_event::TraceConfig& trace_config) {
   // Activate kernel tracing.
   if (!StartKernelSessionTracing())
     return false;
@@ -52,14 +56,15 @@ bool EtwSystemEventConsumer::StartSystemTracing() {
   return true;
 }
 
-void EtwSystemEventConsumer::StopSystemTracing(const OutputCallback& callback) {
+void EtwSystemEventConsumer::StopAgentTracing(
+    const StopAgentTracingCallback& callback) {
   // Deactivate kernel tracing.
   if (!StopKernelSessionTracing()) {
     LOG(FATAL) << "Could not stop system tracing.";
   }
 
   // Stop consuming and flush events.
-  OutputCallback on_stop_system_tracing_done_callback =
+  StopAgentTracingCallback on_stop_system_tracing_done_callback =
       base::Bind(&EtwSystemEventConsumer::OnStopSystemTracingDone,
                  base::Unretained(this),
                  callback);
@@ -69,7 +74,7 @@ void EtwSystemEventConsumer::StopSystemTracing(const OutputCallback& callback) {
 }
 
 void EtwSystemEventConsumer::OnStopSystemTracingDone(
-    const OutputCallback& callback,
+    const StopAgentTracingCallback& callback,
     const scoped_refptr<base::RefCountedString>& result) {
 
   // Stop the consumer thread.
@@ -79,6 +84,19 @@ void EtwSystemEventConsumer::OnStopSystemTracingDone(
   callback.Run(result);
 }
 
+bool EtwSystemEventConsumer::SupportsExplicitClockSync() {
+  return false;
+}
+
+void EtwSystemEventConsumer::RecordClockSyncMarker(
+    scoped_ptr<base::DictionaryValue> marker) {
+  DCHECK(SupportsExplicitClockSync());
+}
+
+void EtwSystemEventConsumer::IssueClockSyncMarker() {
+  DCHECK(SupportsExplicitClockSync());
+}
+
 bool EtwSystemEventConsumer::StartKernelSessionTracing() {
   // Enabled flags (tracing facilities).
   uint32 enabled_flags = EVENT_TRACE_FLAG_IMAGE_LOAD |
@@ -209,7 +227,8 @@ void EtwSystemEventConsumer::TraceAndConsumeOnThread() {
   Close();
 }
 
-void EtwSystemEventConsumer::FlushOnThread(const OutputCallback& callback) {
+void EtwSystemEventConsumer::FlushOnThread(
+    const StopAgentTracingCallback& callback) {
   // Add the header information to the stream.
   scoped_ptr<base::DictionaryValue> header(new base::DictionaryValue());
   header->Set("name", new base::StringValue("ETW"));