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

ui/latency/latency_info.h

Index: ui/latency/latency_info.h
diff --git a/ui/latency/latency_info.h b/ui/latency/latency_info.h
index 218dce92fdb0de81ddbbdc84b26b45c809511b0c..5ded16ed2763eed1e74562238c21ecd5714d4d8d 100644
--- a/ui/latency/latency_info.h
+++ b/ui/latency/latency_info.h
@@ -117,10 +117,6 @@ enum SourceEventType {
 class LatencyInfo {
  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
@@ -131,8 +127,6 @@ class LatencyInfo {
     base::TimeTicks last_event_time;
   };
 
-  enum : size_t { kMaxInputCoordinates = 2 };
-
   // Map a Latency Component (with a component-specific int64_t id) to a
   // component info.
   using LatencyMap = base::flat_map<std::pair<LatencyComponentType, int64_t>,
@@ -164,23 +158,19 @@ class LatencyInfo {
 
   // Modifies the current sequence number for a component, and adds a new
   // sequence number with the current timestamp.
-  void AddLatencyNumber(LatencyComponentType component,
-                        int64_t id,
-                        int64_t component_sequence_number);
+  void AddLatencyNumber(LatencyComponentType component, int64_t id);
 
   // Similar to |AddLatencyNumber|, and also appends |trace_name_str| to
   // the trace event's name.
   // This function should only be called when adding a BEGIN component.
   void AddLatencyNumberWithTraceName(LatencyComponentType component,
                                      int64_t id,
-                                     int64_t component_sequence_number,
                                      const char* trace_name_str);
 
   // Modifies the current sequence number and adds a certain number of events
   // for a specific component.
   void AddLatencyNumberWithTimestamp(LatencyComponentType component,
                                      int64_t id,
-                                     int64_t component_sequence_number,
                                      base::TimeTicks time,
                                      uint32_t event_count);
 
@@ -227,7 +217,6 @@ class LatencyInfo {
  private:
   void AddLatencyNumberWithTimestampImpl(LatencyComponentType component,
                                          int64_t id,
-                                         int64_t component_sequence_number,
                                          base::TimeTicks time,
                                          uint32_t event_count,
                                          const char* trace_name_str);
@@ -242,7 +231,8 @@ class LatencyInfo {
 
   LatencyMap latency_components_;
 
-  // The unique id for matching the ASYNC_BEGIN/END trace event.
+  // The unique id for matching the ASYNC_BEGIN/END trace event. -1 until a
+  // begin component has been encountered.
   int64_t trace_id_;
   // Whether this event has been coalesced into another event.
   bool coalesced_;