Add ScrollBegin.Touch/Wheel Event to UKM

ui/latency/latency_tracker.cc

 // Copyright 2017 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.
 
 #include "ui/latency/latency_tracker.h"
 
 #include "base/metrics/histogram_functions.h"
 #include "base/metrics/histogram_macros.h"
 #include "ui/latency/latency_histogram_macros.h"
 
@@ skipping 141 matching lines @@
     // scroll event's underlying touch/wheel event.
     UMA_HISTOGRAM_INPUT_LATENCY_HIGH_RESOLUTION_MICROSECONDS(
         "Event.Latency.ScrollBegin." + input_modality +
             ".TimeToScrollUpdateSwapBegin2",
         original_component, gpu_swap_begin_component);
 
     ReportRapporScrollLatency("Event.Latency.ScrollBegin." + input_modality +
                                   ".TimeToScrollUpdateSwapBegin2",
                               original_component, gpu_swap_begin_component);
 
+    ReportUkmScrollLatency("Event.ScrollBegin." + input_modality,
+                           "TimeToScrollUpdateSwapBegin", original_component,
+                           gpu_swap_begin_component);
+
     // TODO(lanwei): Will remove them when M56 is stable, see
     // https://crbug.com/669618.
     UMA_HISTOGRAM_INPUT_LATENCY_HIGH_RESOLUTION_MICROSECONDS(
         "Event.Latency.ScrollUpdate." + input_modality +
             ".TimeToFirstScrollUpdateSwapBegin2",
         original_component, gpu_swap_begin_component);
   } else if (latency.FindLatency(
                  ui::INPUT_EVENT_LATENCY_SCROLL_UPDATE_ORIGINAL_COMPONENT,
                  &original_component)) {
     // This UMA metric tracks the time from when the original touch event is
     // created to when the scroll gesture results in final frame swap.
     // First scroll events are excluded from this metric.
     if (input_modality == "Touch") {
       UMA_HISTOGRAM_INPUT_LATENCY_HIGH_RESOLUTION_MICROSECONDS(
           "Event.Latency.ScrollUpdate.Touch.TimeToScrollUpdateSwapBegin2",
           original_component, gpu_swap_begin_component);
 
       ReportRapporScrollLatency(
           "Event.Latency.ScrollUpdate.Touch.TimeToScrollUpdateSwapBegin2",
           original_component, gpu_swap_begin_component);
+
       ReportUkmScrollLatency("Event.ScrollUpdate.Touch",
                              "TimeToScrollUpdateSwapBegin", original_component,
                              gpu_swap_begin_component);
     }
   } else if (latency.FindLatency(ui::INPUT_EVENT_LATENCY_ORIGINAL_COMPONENT, 0,
                                  &original_component)) {
     if (input_modality == "KeyPress") {
       UMA_HISTOGRAM_INPUT_LATENCY_HIGH_RESOLUTION_MICROSECONDS(
           "Event.Latency.EndToEnd.KeyPress", original_component,
           gpu_swap_begin_component);
@@ skipping 45 matching lines @@
       "Event.Latency." + scroll_name + "." + input_modality +
           ".BrowserNotifiedToBeforeGpuSwap2",
       browser_received_swap_component, gpu_swap_begin_component);
 
   UMA_HISTOGRAM_SCROLL_LATENCY_SHORT_2(
       "Event.Latency." + scroll_name + "." + input_modality + ".GpuSwap2",
       gpu_swap_begin_component, gpu_swap_end_component);
 }
 
 }  // namespace ui