Added coordinates information to InputLatency

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 <utility>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/containers/small_map.h"
 #include "base/time/time.h"
 #include "ui/events/events_base_export.h"
+#include "ui/gfx/point_f.h"
 
 namespace ui {
 
 enum LatencyComponentType {
   // ---------------------------BEGIN COMPONENT-------------------------------
   // BEGIN COMPONENT is when we show the latency begin in chrome://tracing.
   // Timestamp when the input event is sent from RenderWidgetHost to renderer.
   INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT,
   // Timestamp when the input event is received in plugin.
   INPUT_EVENT_LATENCY_BEGIN_PLUGIN_COMPONENT,
@@ skipping 63 matching lines @@
     // 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.
     base::TimeTicks event_time;
     // Count of events that happened in this component
     uint32 event_count;
   };
 
+  typedef std::vector<gfx::PointF> InputCoordinates;

[Yufeng Shen (Slow to review), 2014/09/08 18:29:01]

I know Jared has concern about dynamic memory allocation in LatnecyInfo. Maybe
just gfx::PointF[12] and a separate size
variable ?

Jared, wdyt ?

[jdduke (slow), 2014/09/08 20:12:20]

Yeah, a vector is a definite no-no here, and an array of 12 also seems excessive
when the 95%+ case is using a single pointer. Why not just include the primary
pointer (or two, handling 99.9% of the use cases with pinch) if you really need
it here?

+
   // Empirically determined constant based on a typical scroll sequence.
   enum { kTypicalMaxComponentsPerLatencyInfo = 6 };
 
   // Map a Latency Component (with a component-specific int64 id) to a
   // component info.
   typedef base::SmallMap<
       std::map<std::pair<LatencyComponentType, int64>, LatencyComponent>,
       kTypicalMaxComponentsPerLatencyInfo> LatencyMap;
 
   LatencyInfo();
@@ skipping 38 matching lines @@
                    LatencyComponent* output) const;
 
   void RemoveLatency(LatencyComponentType type);
 
   void Clear();
 
   // Records the |event_type| in trace buffer as TRACE_EVENT_ASYNC_STEP.
   void TraceEventType(const char* event_type);
 
   LatencyMap latency_components;
+
+  // These coordinates represent window coordinates.
+  InputCoordinates coordinates;
+
   // The unique id for matching the ASYNC_BEGIN/END trace event.
   int64 trace_id;
   // Whether a terminal component has been added.
   bool terminated;
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_LATENCY_INFO_H_