[Systrace] Fix systrace clock syncing issue with BattOr.

systrace/systrace/tracing_agents/ftrace_agent.py

Index: systrace/systrace/tracing_agents/ftrace_agent.py
diff --git a/systrace/systrace/tracing_agents/ftrace_agent.py b/systrace/systrace/tracing_agents/ftrace_agent.py
index cb1e7e15f28c3fa79180cfa8a007219b02159529..476847e6a3311b0890253242719387b2a86c91dc 100644
--- a/systrace/systrace/tracing_agents/ftrace_agent.py
+++ b/systrace/systrace/tracing_agents/ftrace_agent.py
@@ -8,6 +8,7 @@ import py_utils
 
 from systrace import trace_result
 from systrace import tracing_agents
+from telemetry.timeline import trace_data as trace_data_module
 
 
 class FtraceAgentIo(object):
@@ -199,6 +200,11 @@ class FtraceAgent(tracing_agents.TracingAgent):
     self._fio.writeFile(FT_BUFFER_SIZE, "1")
     return trace_result.TraceResult('trace-data', d)
 
+  def CollectAgentTraceData(self, trace_data_builder):
+    d = self._fio.readFile(FT_TRACE)
+    self._fio.writeFile(FT_BUFFER_SIZE, "1")
+    trace_data_builder.AddTraceFor(trace_data_module.FTRACE_DATA_PART, d)
+
   def SupportsExplicitClockSync(self):
     return False