Collecting LatencyInfo in telemetry

tools/perf/metrics/smoothness.py

Index: tools/perf/metrics/smoothness.py
diff --git a/tools/perf/metrics/smoothness.py b/tools/perf/metrics/smoothness.py
index 2a5b96e2eccbaf961d8104bd564a7f2d2bbd88f3..5d2ac90345ea6d8a5309890ca53d03ff6c927037 100644
--- a/tools/perf/metrics/smoothness.py
+++ b/tools/perf/metrics/smoothness.py
@@ -50,9 +50,10 @@ class SmoothnessMetric(Metric):
     timeline_ranges = [ action.GetActiveRangeOnTimeline(timeline_model)
                         for action in self._actions ]
 
+    browser_process = timeline_model.GetProcess(tab.browser.browser_pid)
     renderer_process = timeline_model.GetRendererProcessFromTab(tab)
     self._stats = rendering_stats.RenderingStats(
-        renderer_process, timeline_ranges)
+        renderer_process, browser_process, timeline_ranges)
 
     if not self._stats.frame_times:
       raise NotEnoughFramesError()
@@ -64,6 +65,33 @@ class SmoothnessMetric(Metric):
     self._stats = stats
 
   def AddResults(self, tab, results):

[nduca, 2014/01/13 18:49:32]

needs unit tests

[Yufeng Shen (Slow to review), 2014/01/14 00:05:47]

I assume the unittests for this is a test that starts a simple scrolable webpage
and run the smoothness measurement on it and check that the desired metrics show
in the result.

Currently the chrome side LatencyInfo plumbing has not totally gone
through yet (I am close in landing this CL
https://codereview.chromium.org/123563002/) so don't have a chrome
build that can return the desired input latency metric.

Either I hold off on this CL until 123563002 is landed or I merge this one first
and add the unittests later.

[Yufeng Shen (Slow to review), 2014/01/20 21:59:30]

Test added.

+    if self._stats.mouse_wheel_latency:
+      mean_mouse_wheel_latency = statistics.ArithmeticMean(
+          self._stats.mouse_wheel_latency, len(self._stats.mouse_wheel_latency))
+      results.Add('mean_mouse_wheel_latency', 'ms',
+                  round(mean_mouse_wheel_latency, 3))
+      results.Add('mouse_wheel_latency_75%', 'ms',
+                  statistics.Percentile(self._stats.mouse_wheel_latency, 75.0) )
+
+    if self._stats.gesture_scroll_latency:
+      mean_gesture_scroll_latency = statistics.ArithmeticMean(
+          self._stats.gesture_scroll_latency,
+          len(self._stats.gesture_scroll_latency))
+      results.Add('mean_gesture_scroll_latency', 'ms',
+                  round(mean_gesture_scroll_latency, 3))
+      results.Add('gesture_scroll_latency_75%', 'ms',
+                  statistics.Percentile(self._stats.gesture_scroll_latency,
+                                        75.0) )
+
+    if self._stats.touch_scroll_latency:
+      mean_touch_scroll_latency = statistics.ArithmeticMean(
+          self._stats.touch_scroll_latency,
+          len(self._stats.touch_scroll_latency))
+      results.Add('mean_touch_scroll_latency', 'ms',
+                  round(mean_touch_scroll_latency, 3))
+      results.Add('touch_scroll_latency_75%', 'ms',
+                  statistics.Percentile(self._stats.touch_scroll_latency,
+                                        75.0) )
     # List of raw frame times.
     results.Add('frame_times', 'ms', self._stats.frame_times)