telemetry: Clean up SurfaceFlinger statistics

tools/telemetry/telemetry/core/platform/android_platform_backend.py

Index: tools/telemetry/telemetry/core/platform/android_platform_backend.py
diff --git a/tools/telemetry/telemetry/core/platform/android_platform_backend.py b/tools/telemetry/telemetry/core/platform/android_platform_backend.py
index 16c0d89327b013d6b87fc7e8928cffe84a735aa0..d12c371737eadb89fa38939752420ff0305f49eb 100644
--- a/tools/telemetry/telemetry/core/platform/android_platform_backend.py
+++ b/tools/telemetry/telemetry/core/platform/android_platform_backend.py
@@ -24,6 +24,7 @@ from telemetry.core.platform.power_monitor import android_temperature_monitor
 from telemetry.core.platform.power_monitor import monsoon_power_monitor
 from telemetry.core.platform.power_monitor import power_monitor_controller
 from telemetry.core.platform.profiler import android_prebuilt_profiler_helper
+from telemetry.timeline import surface_flinger_timeline_data
 from telemetry.util import exception_formatter
 
 util.AddDirToPythonPath(util.GetChromiumSrcDir(),
@@ -100,10 +101,10 @@ class AndroidPlatformBackend(
   def adb(self):
     return self._adb
 
-  def IsRawDisplayFrameRateSupported(self):
-    return True
+  def IsDisplayTracingSupported(self):
+    return bool(self.GetOSVersionName() >= 'J')
 
-  def StartRawDisplayFrameRateMeasurement(self):
+  def StartDisplayTracing(self):
     assert not self._surface_stats_collector
     # Clear any leftover data from previous timed out tests
     self._raw_display_frame_rate_measurements = []
@@ -111,22 +112,15 @@ class AndroidPlatformBackend(
         surface_stats_collector.SurfaceStatsCollector(self._device)
     self._surface_stats_collector.Start()
 
-  def StopRawDisplayFrameRateMeasurement(self):
+  def StopDisplayTracing(self):
     if not self._surface_stats_collector:
       return
 
-    self._surface_stats_collector.Stop()
-    for r in self._surface_stats_collector.GetResults():
-      self._raw_display_frame_rate_measurements.append(
-          platform.Platform.RawDisplayFrameRateMeasurement(
-              r.name, r.value, r.unit))
-
+    refresh_period, timestamps = self._surface_stats_collector.Stop()
+    pid = self._surface_stats_collector.GetSurfaceFlingerPid()
     self._surface_stats_collector = None
-
-  def GetRawDisplayFrameRateMeasurements(self):
-    ret = self._raw_display_frame_rate_measurements
-    self._raw_display_frame_rate_measurements = []
-    return ret
+    return surface_flinger_timeline_data.SurfaceFlingerTimelineData(
+        pid, refresh_period, timestamps)
 
   def SetFullPerformanceModeEnabled(self, enabled):
     if not self._enable_performance_mode: