[Tracing Clock Sync] Add TracingAgent interface in Chrome

chromeos/dbus/fake_debug_daemon_client.cc

Index: chromeos/dbus/fake_debug_daemon_client.cc
diff --git a/chromeos/dbus/fake_debug_daemon_client.cc b/chromeos/dbus/fake_debug_daemon_client.cc
index 8dd391cdbb9d549a81a4ee2f29b5a01a9a8763d9..cad4b8814e85e9a19dc428a349b130c51df268a1 100644
--- a/chromeos/dbus/fake_debug_daemon_client.cc
+++ b/chromeos/dbus/fake_debug_daemon_client.cc
@@ -38,16 +38,38 @@ void FakeDebugDaemonClient::SetDebugMode(const std::string& subsystem,
                                          const SetDebugModeCallback& callback) {
   callback.Run(false);
 }
-void FakeDebugDaemonClient::StartSystemTracing() {}
 
-bool FakeDebugDaemonClient::RequestStopSystemTracing(
-    scoped_refptr<base::TaskRunner> task_runner,
-    const StopSystemTracingCallback& callback) {
+std::string FakeDebugDaemonClient::GetTracingAgentName() {
+  return kCrOSTracingAgentName;
+}
+
+bool FakeDebugDaemonClient::StartAgentTracing(
+    const base::trace_event::TraceConfig& trace_config) {
+  return true;
+}
+
+void FakeDebugDaemonClient::StopAgentTracing(
+    const StopAgentTracingCallback& callback) {
   std::string no_data;
   callback.Run(base::RefCountedString::TakeString(&no_data));
-  return true;
 }
 
+bool FakeDebugDaemonClient::SupportsExplicitClockSync() {
+  return false;
+}
+
+void FakeDebugDaemonClient::RecordClockSyncMarker(
+    scoped_ptr<base::DictionaryValue> marker) {
+  DCHECK(SupportsExplicitClockSync());
+}
+
+void FakeDebugDaemonClient::IssueClockSyncMarker() {

[oystein (OOO til 10th of July), 2015/11/24 22:52:10]

The pattern of these three above functions seem to be the default, and repeated
a lot. Maybe this should be the default behavior in the base class, to reduce
the boilerplate?

[Zhen Wang, 2015/11/25 04:24:55]

Done.

+  DCHECK(SupportsExplicitClockSync());
+}
+
+void FakeDebugDaemonClient::SetStopAgentTracingTaskRunner(
+    scoped_refptr<base::TaskRunner> task_runner) {}
+
 void FakeDebugDaemonClient::GetRoutes(bool numeric,
                                       bool ipv6,
                                       const GetRoutesCallback& callback) {