Sync ui/events to chromium @ https://codereview.chromium.org/1210203002

ui/events/latency_info.h

Index: ui/events/latency_info.h
diff --git a/ui/events/latency_info.h b/ui/events/latency_info.h
index b6724b86154ac8dce6948aa4d0ac697bfb768384..ffc9bdbde5e87193925f078ce28bbc7ebad46a43 100644
--- a/ui/events/latency_info.h
+++ b/ui/events/latency_info.h
@@ -5,6 +5,7 @@
 #ifndef UI_EVENTS_LATENCY_INFO_H_
 #define UI_EVENTS_LATENCY_INFO_H_
 
+#include <string>
 #include <utility>
 #include <vector>
 
@@ -22,8 +23,10 @@ enum LatencyComponentType {
   INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT,
   // Timestamp when the input event is received in plugin.
   INPUT_EVENT_LATENCY_BEGIN_PLUGIN_COMPONENT,
-  // Timestamp when a scroll update for the main thread is begun.
-  INPUT_EVENT_LATENCY_BEGIN_SCROLL_UPDATE_MAIN_COMPONENT,
+  // In threaded scrolling, main thread scroll listener update is async to
+  // scroll processing in impl thread. This is the timestamp when we consider
+  // the main thread scroll listener update is begun.
+  LATENCY_BEGIN_SCROLL_LISTENER_UPDATE_MAIN_COMPONENT,
   // ---------------------------NORMAL COMPONENT-------------------------------
   // The original timestamp of the touch event which converts to scroll update.
   INPUT_EVENT_LATENCY_SCROLL_UPDATE_ORIGINAL_COMPONENT,
@@ -47,10 +50,6 @@ enum LatencyComponentType {
   // Frame number when a window snapshot was requested. The snapshot
   // is taken when the rendering results actually reach the screen.
   WINDOW_SNAPSHOT_FRAME_NUMBER_COMPONENT,
-  // Frame number for a snapshot requested via
-  // gpuBenchmarking.beginWindowSnapshotPNG
-  // TODO(vkuzkokov): remove when patch adding this hits Stable
-  WINDOW_OLD_SNAPSHOT_FRAME_NUMBER_COMPONENT,
   // Timestamp when a tab is requested to be shown.
   TAB_SHOW_COMPONENT,
   // Timestamp when the frame is swapped in renderer.
@@ -147,6 +146,14 @@ struct EVENTS_BASE_EXPORT LatencyInfo {
                         int64 id,
                         int64 component_sequence_number);
 
+  // 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 id,
+                                     int64 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,
@@ -155,6 +162,13 @@ struct EVENTS_BASE_EXPORT LatencyInfo {
                                      base::TimeTicks time,
                                      uint32 event_count);
 
+  void AddLatencyNumberWithTimestampImpl(LatencyComponentType component,
+                                         int64 id,
+                                         int64 component_sequence_number,
+                                         base::TimeTicks time,
+                                         uint32 event_count,
+                                         const char* trace_name_str);
+
   // Returns true if the a component with |type| and |id| is found in
   // the latency_components and the component is stored to |output| if
   // |output| is not NULL. Returns false if no such component is found.
@@ -166,8 +180,9 @@ struct EVENTS_BASE_EXPORT LatencyInfo {
 
   void Clear();
 
-  // Records the |event_type| in trace buffer as TRACE_EVENT_ASYNC_STEP.
-  void TraceEventType(const char* event_type);
+  // Shown as part of the name of the trace event for this LatencyInfo.
+  // String is empty if no tracing is enabled.
+  std::string trace_name;
 
   LatencyMap latency_components;