New scroll latency metrics added for touch and wheel.

ui/events/latency_info.h

 // 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.
 
 #ifndef UI_EVENTS_LATENCY_INFO_H_
 #define UI_EVENTS_LATENCY_INFO_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 119 matching lines @@
  public:
   struct LatencyComponent {
     // Nondecreasing number that can be used to determine what events happened
     // in the component at the time this struct was sent on to the next
     // component.
     int64_t sequence_number;
     // Average time of events that happened in this component.
     base::TimeTicks event_time;
     // Count of events that happened in this component
     uint32_t event_count;
+    // Time of the oldest event that happened in this component.
+    base::TimeTicks first_event_time;
+    // Time of the most recent event that happened in this component.
+    base::TimeTicks last_event_time;
   };
 
   // Empirically determined constant based on a typical scroll sequence.
   enum { kTypicalMaxComponentsPerLatencyInfo = 10 };
 
   enum : size_t { kMaxInputCoordinates = 2 };
 
   // Map a Latency Component (with a component-specific int64_t id) to a
   // component info.
   typedef base::SmallMap<
@@ skipping 112 matching lines @@
 #if !defined(OS_IOS)
   friend struct IPC::ParamTraits<ui::LatencyInfo>;
   friend struct mojo::StructTraits<ui::mojom::LatencyInfoDataView,
                                    ui::LatencyInfo>;
 #endif
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_LATENCY_INFO_H_