Add touch drag UMA latency metric.

ui/events/latency_info.cc

 // 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.
 
 #include "ui/events/latency_info.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <string>
@@ skipping 10 matching lines @@
 
 const char* GetComponentName(ui::LatencyComponentType type) {
 #define CASE_TYPE(t) case ui::t:  return #t
   switch (type) {
     CASE_TYPE(INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT);
     CASE_TYPE(LATENCY_BEGIN_SCROLL_LISTENER_UPDATE_MAIN_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_SCROLL_UPDATE_ORIGINAL_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_FIRST_SCROLL_UPDATE_ORIGINAL_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_ORIGINAL_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_UI_COMPONENT);
+    CASE_TYPE(INPUT_EVENT_LATENCY_REACHED_RWH_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_RENDERING_SCHEDULED_MAIN_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_RENDERING_SCHEDULED_IMPL_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_FORWARD_SCROLL_UPDATE_TO_MAIN_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_ACK_RWH_COMPONENT);
     CASE_TYPE(WINDOW_SNAPSHOT_FRAME_NUMBER_COMPONENT);
     CASE_TYPE(TAB_SHOW_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_RENDERER_SWAP_COMPONENT);
     CASE_TYPE(INPUT_EVENT_BROWSER_RECEIVED_RENDERER_SWAP_COMPONENT);
     CASE_TYPE(INPUT_EVENT_GPU_SWAP_BUFFER_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_MOUSE_COMPONENT);
@@ skipping 332 matching lines @@
 }
 
 bool LatencyInfo::AddInputCoordinate(const InputCoordinate& input_coordinate) {
   if (input_coordinates_size_ >= kMaxInputCoordinates)
     return false;
   input_coordinates_[input_coordinates_size_++] = input_coordinate;
   return true;
 }
 
 }  // namespace ui