Remove LatencyInfo::sequence_number. (May break metrics).

ui/latency/mojo/latency_info.mojom

 // Copyright 2016 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.
 
 module ui.mojom;
 
 import "mojo/common/time.mojom";
 import "ui/gfx/geometry/mojo/geometry.mojom";
 
 enum LatencyComponentType {
@@ skipping 72 matching lines @@
   OTHER,
   SOURCE_EVENT_TYPE_LAST = OTHER,
 };
 
 struct LatencyComponentId {
   LatencyComponentType type;
   int64 id;
 };
 
 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 sequence_number;
   // Average time of events that happened in this component.
   mojo.common.mojom.TimeTicks event_time;
   // Count of events that happened in this component
   uint32 event_count;
   // Time of the oldest event that happened in this component.
   mojo.common.mojom.TimeTicks first_event_time;
   // Time of the most recent event that happened in this component.
   mojo.common.mojom.TimeTicks last_event_time;
 };
 
 struct LatencyComponentPair {
   LatencyComponentId key;
   LatencyComponent value;
 };
 
 // See ui/latency/latency_info.h
 struct LatencyInfo {
   string trace_name;
   array<LatencyComponentPair> latency_components;
   int64 trace_id;
   bool coalesced;
   bool began;
   bool terminated;
   SourceEventType source_event_type;
   mojo.common.mojom.TimeDelta expected_queueing_time_on_dispatch;
 };