New scroll latency metrics added for touch and wheel.

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 261 matching lines @@
     TRACE_EVENT_WITH_FLOW1("input,benchmark",
                            "LatencyInfo.Flow",
                            TRACE_ID_DONT_MANGLE(trace_id_),
                            TRACE_EVENT_FLAG_FLOW_OUT,
                            "trace_id", trace_id_);
   }
 
   LatencyMap::key_type key = std::make_pair(component, id);
   LatencyMap::iterator it = latency_components_.find(key);
   if (it == latency_components_.end()) {
-    LatencyComponent info = {component_sequence_number, time, event_count};
+    LatencyComponent info = {component_sequence_number, time, event_count, time,
+                             time};
     latency_components_[key] = info;
   } else {
     it->second.sequence_number = std::max(component_sequence_number,
                                           it->second.sequence_number);
     uint32_t new_count = event_count + it->second.event_count;
     if (event_count > 0 && new_count != 0) {
       // Do a weighted average, so that the new event_time is the average of
       // the times of events currently in this structure with the time passed
       // into this method.
       it->second.event_time += (time - it->second.event_time) * event_count /
           new_count;
       it->second.event_count = new_count;
+      it->second.last_event_time = std::max(it->second.last_event_time, time);
     }
   }
 
   if (IsTerminalComponent(component) && trace_id_ != -1) {
     // Should only ever add terminal component once.
     CHECK(!terminated_);
     terminated_ = true;
 
     if (*latency_info_enabled) {
       TRACE_EVENT_COPY_ASYNC_END2(kTraceCategoriesForAsyncEvents,
@@ skipping 67 matching lines @@
 }
 
 bool LatencyInfo::AddInputCoordinate(const gfx::PointF& input_coordinate) {
   if (input_coordinates_size_ >= kMaxInputCoordinates)
     return false;
   input_coordinates_[input_coordinates_size_++] = input_coordinate;
   return true;
 }
 
 }  // namespace ui