Collect touch scroll latency for JS driven scroll

tools/perf/metrics/rendering_stats.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 from operator import attrgetter
 
 # These are LatencyInfo component names indicating the various components
 # that the input event has travelled through.
 # This is when the input event first reaches chrome.
 UI_COMP_NAME = 'INPUT_EVENT_LATENCY_UI_COMPONENT'
 # This is when the input event was originally created by OS.
 ORIGINAL_COMP_NAME = 'INPUT_EVENT_LATENCY_ORIGINAL_COMPONENT'
 # This is when the input event was sent from browser to renderer.
 BEGIN_COMP_NAME = 'INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT'
 # This is when the input event has reached swap buffer.
 END_COMP_NAME = 'INPUT_EVENT_LATENCY_TERMINATED_FRAME_SWAP_COMPONENT'
 
 def GetScrollInputLatencyEvents(browser_process, timeline_range):
   """Get scroll events' LatencyInfo from the browser process's trace buffer
      that are within the timeline_range.
 
-  Scroll events (MouseWheel or GestureScrollUpdate) dump their LatencyInfo
-  into trace buffer as async trace event with name "InputLatency". The trace
-  event has a memeber 'step' containing its event type and a memeber 'data'
-  containing its latency history.
+  Scroll events (MouseWheel, GestureScrollUpdate or JS scroll on TouchMove)
+  dump their LatencyInfo into trace buffer as async trace event with name
+  "InputLatency". The trace event has a memeber 'step' containing its event
+  type and a memeber 'data' containing its latency history.
 
   """
   mouse_wheel_events = []
   touch_scroll_events = []
   if not browser_process:
     return (mouse_wheel_events, touch_scroll_events)
   for event in browser_process.IterAllAsyncSlicesOfName("InputLatency"):
     if event.start >= timeline_range.min and event.end <= timeline_range.max:
       for ss in event.sub_slices:
         if 'step' not in ss.args:
           continue
         if 'data' not in ss.args:
           continue
         if ss.args['step'] == 'MouseWheel':
           mouse_wheel_events.append(ss)
         elif ss.args['step'] == 'GestureScrollUpdate':
           touch_scroll_events.append(ss)
+        elif ss.args['step'] == 'TouchMove':
+          touch_scroll_events.append(ss)
   return (mouse_wheel_events, touch_scroll_events)
 
 def ComputeMouseWheelScrollLatency(mouse_wheel_events):
   """ Compute the mouse wheel scroll latency.
 
   Mouse wheel scroll latency is the time from when mouse wheel event is sent
   from browser RWH to renderer (the timestamp of component
   'INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT') to when the scrolled page is
   buffer swapped (the timestamp of component
   'INPUT_EVENT_LATENCY_TERMINATED_FRAME_SWAP_COMPONENT')
@@ skipping 138 matching lines @@
         self.frame_timestamps[-1].append(
             event.start)
         if not first_frame:
           self.frame_times[-1].append(round(self.frame_timestamps[-1][-1] -
                                             self.frame_timestamps[-1][-2], 2))
         first_frame = False
       self.rasterize_times[-1].append(1000.0 *
           event.args['data']['rasterize_time'])
       self.rasterized_pixel_counts[-1].append(
           event.args['data']['rasterized_pixel_count'])