ui/events/latency_info.cc - chromium/src - Git at Google

 // 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.

 #include "ui/events/latency_info.h"

 #include <stddef.h>

 #include <algorithm>
 #include <string>
 #include <utility>

 #include "base/json/json_writer.h"
 #include "base/lazy_instance.h"
 #include "base/macros.h"
 #include "base/strings/stringprintf.h"

 namespace {

 const size_t kMaxLatencyInfoNumber = 100;

 const char* GetComponentName(ui::LatencyComponentType type) {
 #define CASE_TYPE(t) case ui::t:  return #t
   switch (type) {
     CASE_TYPE(INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT);
     CASE_TYPE(LATENCY_BEGIN_SCROLL_LISTENER_UPDATE_MAIN_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_SCROLL_UPDATE_ORIGINAL_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_FIRST_SCROLL_UPDATE_ORIGINAL_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_ORIGINAL_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_UI_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_RENDERING_SCHEDULED_MAIN_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_RENDERING_SCHEDULED_IMPL_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_FORWARD_SCROLL_UPDATE_TO_MAIN_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_ACK_RWH_COMPONENT);
     CASE_TYPE(WINDOW_SNAPSHOT_FRAME_NUMBER_COMPONENT);
     CASE_TYPE(TAB_SHOW_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_RENDERER_MAIN_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_RENDERER_SWAP_COMPONENT);
     CASE_TYPE(INPUT_EVENT_BROWSER_RECEIVED_RENDERER_SWAP_COMPONENT);
     CASE_TYPE(INPUT_EVENT_GPU_SWAP_BUFFER_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_GENERATE_SCROLL_UPDATE_FROM_MOUSE_WHEEL);
     CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_MOUSE_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_MOUSE_WHEEL_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_KEYBOARD_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_TOUCH_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_GESTURE_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_FRAME_SWAP_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_COMMIT_FAILED_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_COMMIT_NO_UPDATE_COMPONENT);
     CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_SWAP_FAILED_COMPONENT);
     default:
       DLOG(WARNING) << "Unhandled LatencyComponentType.\n";
       break;
   }
 #undef CASE_TYPE
   return "unknown";
 }

 bool IsTerminalComponent(ui::LatencyComponentType type) {
   switch (type) {
     case ui::INPUT_EVENT_LATENCY_TERMINATED_MOUSE_COMPONENT:
     case ui::INPUT_EVENT_LATENCY_TERMINATED_MOUSE_WHEEL_COMPONENT:
     case ui::INPUT_EVENT_LATENCY_TERMINATED_KEYBOARD_COMPONENT:
     case ui::INPUT_EVENT_LATENCY_TERMINATED_TOUCH_COMPONENT:
     case ui::INPUT_EVENT_LATENCY_TERMINATED_GESTURE_COMPONENT:
     case ui::INPUT_EVENT_LATENCY_TERMINATED_FRAME_SWAP_COMPONENT:
     case ui::INPUT_EVENT_LATENCY_TERMINATED_COMMIT_FAILED_COMPONENT:
     case ui::INPUT_EVENT_LATENCY_TERMINATED_COMMIT_NO_UPDATE_COMPONENT:
     case ui::INPUT_EVENT_LATENCY_TERMINATED_SWAP_FAILED_COMPONENT:
       return true;
     default:
       return false;
   }
 }

 bool IsBeginComponent(ui::LatencyComponentType type) {
   return (type == ui::INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT ||
           type == ui::LATENCY_BEGIN_SCROLL_LISTENER_UPDATE_MAIN_COMPONENT);
 }

 bool IsInputLatencyBeginComponent(ui::LatencyComponentType type) {
   return type == ui::INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT;
 }

 // This class is for converting latency info to trace buffer friendly format.
 class LatencyInfoTracedValue
     : public base::trace_event::ConvertableToTraceFormat {
  public:
   static std::unique_ptr<ConvertableToTraceFormat> FromValue(
       std::unique_ptr<base::Value> value);

   void AppendAsTraceFormat(std::string* out) const override;

  private:
   explicit LatencyInfoTracedValue(base::Value* value);
   ~LatencyInfoTracedValue() override;

   std::unique_ptr<base::Value> value_;

   DISALLOW_COPY_AND_ASSIGN(LatencyInfoTracedValue);
 };

 std::unique_ptr<base::trace_event::ConvertableToTraceFormat>
 LatencyInfoTracedValue::FromValue(std::unique_ptr<base::Value> value) {
   return std::unique_ptr<base::trace_event::ConvertableToTraceFormat>(
       new LatencyInfoTracedValue(value.release()));
 }

 LatencyInfoTracedValue::~LatencyInfoTracedValue() {
 }

 void LatencyInfoTracedValue::AppendAsTraceFormat(std::string* out) const {
   std::string tmp;
   base::JSONWriter::Write(*value_, &tmp);
   *out += tmp;
 }

 LatencyInfoTracedValue::LatencyInfoTracedValue(base::Value* value)
     : value_(value) {
 }

 const char kTraceCategoriesForAsyncEvents[] = "benchmark,latencyInfo";

 struct LatencyInfoEnabledInitializer {
   LatencyInfoEnabledInitializer() :
       latency_info_enabled(TRACE_EVENT_API_GET_CATEGORY_GROUP_ENABLED(
           kTraceCategoriesForAsyncEvents)) {
   }

   const unsigned char* latency_info_enabled;
 };

 static base::LazyInstance<LatencyInfoEnabledInitializer>::Leaky
   g_latency_info_enabled = LAZY_INSTANCE_INITIALIZER;

 }  // namespace

 namespace ui {

 LatencyInfo::InputCoordinate::InputCoordinate() : x(0), y(0) {
 }

 LatencyInfo::InputCoordinate::InputCoordinate(float x, float y) : x(x), y(y) {
 }

 LatencyInfo::LatencyInfo()
     : input_coordinates_size_(0),
       trace_id_(-1),
       coalesced_(false),
       terminated_(false) {}

 LatencyInfo::LatencyInfo(const LatencyInfo& other) = default;

 LatencyInfo::~LatencyInfo() {}

 LatencyInfo::LatencyInfo(int64_t trace_id, bool terminated)
     : input_coordinates_size_(0),
       trace_id_(trace_id),
       terminated_(terminated) {}

 bool LatencyInfo::Verify(const std::vector<LatencyInfo>& latency_info,
                          const char* referring_msg) {
   if (latency_info.size() > kMaxLatencyInfoNumber) {
     LOG(ERROR) << referring_msg << ", LatencyInfo vector size "
                << latency_info.size() << " is too big.";
     TRACE_EVENT_INSTANT1("input,benchmark", "LatencyInfo::Verify Fails",
                          TRACE_EVENT_SCOPE_GLOBAL,
                          "size", latency_info.size());
     return false;
   }
   return true;
 }

 void LatencyInfo::CopyLatencyFrom(const LatencyInfo& other,
                                   LatencyComponentType type) {
   for (const auto& lc : other.latency_components()) {
     if (lc.first.first == type) {
       AddLatencyNumberWithTimestamp(lc.first.first,
                                     lc.first.second,
                                     lc.second.sequence_number,
                                     lc.second.event_time,
                                     lc.second.event_count);
     }
   }
 }

 void LatencyInfo::AddNewLatencyFrom(const LatencyInfo& other) {
   for (const auto& lc : other.latency_components()) {
     if (!FindLatency(lc.first.first, lc.first.second, NULL)) {
       AddLatencyNumberWithTimestamp(lc.first.first,
                                     lc.first.second,
                                     lc.second.sequence_number,
                                     lc.second.event_time,
                                     lc.second.event_count);
     }
   }
 }

 void LatencyInfo::AddLatencyNumber(LatencyComponentType component,
                                    int64_t id,
                                    int64_t component_sequence_number) {
   AddLatencyNumberWithTimestampImpl(component, id, component_sequence_number,
                                     base::TimeTicks::Now(), 1, nullptr);
 }

 void LatencyInfo::AddLatencyNumberWithTraceName(
     LatencyComponentType component,
     int64_t id,
     int64_t component_sequence_number,
     const char* trace_name_str) {
   AddLatencyNumberWithTimestampImpl(component, id, component_sequence_number,
                                     base::TimeTicks::Now(), 1, trace_name_str);
 }

 void LatencyInfo::AddLatencyNumberWithTimestamp(
     LatencyComponentType component,
     int64_t id,
     int64_t component_sequence_number,
     base::TimeTicks time,
     uint32_t event_count) {
   AddLatencyNumberWithTimestampImpl(component, id, component_sequence_number,
                                     time, event_count, nullptr);
 }

 void LatencyInfo::AddLatencyNumberWithTimestampImpl(
     LatencyComponentType component,
     int64_t id,
     int64_t component_sequence_number,
     base::TimeTicks time,
     uint32_t event_count,
     const char* trace_name_str) {
   const unsigned char* latency_info_enabled =
       g_latency_info_enabled.Get().latency_info_enabled;

   if (IsBeginComponent(component)) {
     // Should only ever add begin component once.
     CHECK_EQ(-1, trace_id_);
     trace_id_ = component_sequence_number;

     if (*latency_info_enabled) {
       // The timestamp for ASYNC_BEGIN trace event is used for drawing the
       // beginning of the trace event in trace viewer. For better visualization,
       // for an input event, we want to draw the beginning as when the event is
       // originally created, e.g. the timestamp of its ORIGINAL/UI_COMPONENT,
       // not when we actually issue the ASYNC_BEGIN trace event.
       LatencyComponent begin_component;
       int64_t ts = 0;
       if (FindLatency(INPUT_EVENT_LATENCY_ORIGINAL_COMPONENT,
                       0,
                       &begin_component) ||
           FindLatency(INPUT_EVENT_LATENCY_UI_COMPONENT,
                       0,
                       &begin_component)) {
         ts = begin_component.event_time.ToInternalValue();
       } else {
         ts = base::TimeTicks::Now().ToInternalValue();
       }

       if (trace_name_str) {
         if (IsInputLatencyBeginComponent(component))
           trace_name_ = std::string("InputLatency::") + trace_name_str;
         else
           trace_name_ = std::string("Latency::") + trace_name_str;
       }

       TRACE_EVENT_COPY_ASYNC_BEGIN_WITH_TIMESTAMP0(
           kTraceCategoriesForAsyncEvents,
           trace_name_.c_str(),
           TRACE_ID_DONT_MANGLE(trace_id_),
           ts);
     }

     TRACE_EVENT_WITH_FLOW1("input,benchmark",
                            "LatencyInfo.Flow",
                            TRACE_ID_DONT_MANGLE(trace_id_),
                            TRACE_EVENT_FLAG_FLOW_OUT,
                            "trace_id", trace_id_);
   }

   LatencyMap::key_type key = std::make_pair(component, id);
   LatencyMap::iterator it = latency_components_.find(key);
   if (it == latency_components_.end()) {
     LatencyComponent info = {component_sequence_number, time, event_count};
     latency_components_[key] = info;
   } else {
     it->second.sequence_number = std::max(component_sequence_number,
                                           it->second.sequence_number);
     uint32_t new_count = event_count + it->second.event_count;
     if (event_count > 0 && new_count != 0) {
       // Do a weighted average, so that the new event_time is the average of
       // the times of events currently in this structure with the time passed
       // into this method.
       it->second.event_time += (time - it->second.event_time) * event_count /
           new_count;
       it->second.event_count = new_count;
     }
   }

   if (IsTerminalComponent(component) && trace_id_ != -1) {
     // Should only ever add terminal component once.
     CHECK(!terminated_);
     terminated_ = true;

     if (*latency_info_enabled) {
       TRACE_EVENT_COPY_ASYNC_END2(kTraceCategoriesForAsyncEvents,
                                   trace_name_.c_str(),
                                   TRACE_ID_DONT_MANGLE(trace_id_),
                                   "data", AsTraceableData(),
                                   "coordinates", CoordinatesAsTraceableData());
     }

     TRACE_EVENT_WITH_FLOW0("input,benchmark",
                            "LatencyInfo.Flow",
                            TRACE_ID_DONT_MANGLE(trace_id_),
                            TRACE_EVENT_FLAG_FLOW_IN);
   }
 }

 std::unique_ptr<base::trace_event::ConvertableToTraceFormat>
 LatencyInfo::AsTraceableData() {
   std::unique_ptr<base::DictionaryValue> record_data(
       new base::DictionaryValue());
   for (const auto& lc : latency_components_) {
     std::unique_ptr<base::DictionaryValue> component_info(
         new base::DictionaryValue());
     component_info->SetDouble("comp_id", static_cast<double>(lc.first.second));
     component_info->SetDouble(
         "time",
         static_cast<double>(lc.second.event_time.ToInternalValue()));
     component_info->SetDouble("count", lc.second.event_count);
     component_info->SetDouble("sequence_number",
                               lc.second.sequence_number);
     record_data->Set(GetComponentName(lc.first.first),
                      std::move(component_info));
   }
   record_data->SetDouble("trace_id", static_cast<double>(trace_id_));
   return LatencyInfoTracedValue::FromValue(std::move(record_data));
 }

 std::unique_ptr<base::trace_event::ConvertableToTraceFormat>
 LatencyInfo::CoordinatesAsTraceableData() {
   std::unique_ptr<base::ListValue> coordinates(new base::ListValue());
   for (size_t i = 0; i < input_coordinates_size_; i++) {
     std::unique_ptr<base::DictionaryValue> coordinate_pair(
         new base::DictionaryValue());
     coordinate_pair->SetDouble("x", input_coordinates_[i].x);
     coordinate_pair->SetDouble("y", input_coordinates_[i].y);
     coordinates->Append(coordinate_pair.release());
   }
   return LatencyInfoTracedValue::FromValue(std::move(coordinates));
 }

 bool LatencyInfo::FindLatency(LatencyComponentType type,
                               int64_t id,
                               LatencyComponent* output) const {
   LatencyMap::const_iterator it = latency_components_.find(
       std::make_pair(type, id));
   if (it == latency_components_.end())
     return false;
   if (output)
     *output = it->second;
   return true;
 }

 void LatencyInfo::RemoveLatency(LatencyComponentType type) {
   LatencyMap::iterator it = latency_components_.begin();
   while (it != latency_components_.end()) {
     if (it->first.first == type) {
       LatencyMap::iterator tmp = it;
       ++it;
       latency_components_.erase(tmp);
     } else {
       it++;
     }
   }
 }

 bool LatencyInfo::AddInputCoordinate(const InputCoordinate& input_coordinate) {
   if (input_coordinates_size_ >= kMaxInputCoordinates)
     return false;
   input_coordinates_[input_coordinates_size_++] = input_coordinate;
   return true;
 }

 }  // namespace ui
	// 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.

	#include "ui/events/latency_info.h"

	#include <stddef.h>

	#include <algorithm>
	#include <string>
	#include <utility>

	#include "base/json/json_writer.h"
	#include "base/lazy_instance.h"
	#include "base/macros.h"
	#include "base/strings/stringprintf.h"

	namespace {

	const size_t kMaxLatencyInfoNumber = 100;

	const char* GetComponentName(ui::LatencyComponentType type) {
	#define CASE_TYPE(t) case ui::t: return #t
	switch (type) {
	CASE_TYPE(INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT);
	CASE_TYPE(LATENCY_BEGIN_SCROLL_LISTENER_UPDATE_MAIN_COMPONENT);
	CASE_TYPE(INPUT_EVENT_LATENCY_SCROLL_UPDATE_ORIGINAL_COMPONENT);
	CASE_TYPE(INPUT_EVENT_LATENCY_FIRST_SCROLL_UPDATE_ORIGINAL_COMPONENT);
	CASE_TYPE(INPUT_EVENT_LATENCY_ORIGINAL_COMPONENT);
	CASE_TYPE(INPUT_EVENT_LATENCY_UI_COMPONENT);
	CASE_TYPE(INPUT_EVENT_LATENCY_RENDERING_SCHEDULED_MAIN_COMPONENT);
	CASE_TYPE(INPUT_EVENT_LATENCY_RENDERING_SCHEDULED_IMPL_COMPONENT);
	CASE_TYPE(INPUT_EVENT_LATENCY_FORWARD_SCROLL_UPDATE_TO_MAIN_COMPONENT);
	CASE_TYPE(INPUT_EVENT_LATENCY_ACK_RWH_COMPONENT);
	CASE_TYPE(WINDOW_SNAPSHOT_FRAME_NUMBER_COMPONENT);
	CASE_TYPE(TAB_SHOW_COMPONENT);
	CASE_TYPE(INPUT_EVENT_LATENCY_RENDERER_MAIN_COMPONENT);
	CASE_TYPE(INPUT_EVENT_LATENCY_RENDERER_SWAP_COMPONENT);
	CASE_TYPE(INPUT_EVENT_BROWSER_RECEIVED_RENDERER_SWAP_COMPONENT);
	CASE_TYPE(INPUT_EVENT_GPU_SWAP_BUFFER_COMPONENT);
	CASE_TYPE(INPUT_EVENT_LATENCY_GENERATE_SCROLL_UPDATE_FROM_MOUSE_WHEEL);
	CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_MOUSE_COMPONENT);
	CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_MOUSE_WHEEL_COMPONENT);
	CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_KEYBOARD_COMPONENT);
	CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_TOUCH_COMPONENT);
	CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_GESTURE_COMPONENT);
	CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_FRAME_SWAP_COMPONENT);
	CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_COMMIT_FAILED_COMPONENT);
	CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_COMMIT_NO_UPDATE_COMPONENT);
	CASE_TYPE(INPUT_EVENT_LATENCY_TERMINATED_SWAP_FAILED_COMPONENT);
	default:
	DLOG(WARNING) << "Unhandled LatencyComponentType.\n";
	break;
	}
	#undef CASE_TYPE
	return "unknown";
	}

	bool IsTerminalComponent(ui::LatencyComponentType type) {
	switch (type) {
	case ui::INPUT_EVENT_LATENCY_TERMINATED_MOUSE_COMPONENT:
	case ui::INPUT_EVENT_LATENCY_TERMINATED_MOUSE_WHEEL_COMPONENT:
	case ui::INPUT_EVENT_LATENCY_TERMINATED_KEYBOARD_COMPONENT:
	case ui::INPUT_EVENT_LATENCY_TERMINATED_TOUCH_COMPONENT:
	case ui::INPUT_EVENT_LATENCY_TERMINATED_GESTURE_COMPONENT:
	case ui::INPUT_EVENT_LATENCY_TERMINATED_FRAME_SWAP_COMPONENT:
	case ui::INPUT_EVENT_LATENCY_TERMINATED_COMMIT_FAILED_COMPONENT:
	case ui::INPUT_EVENT_LATENCY_TERMINATED_COMMIT_NO_UPDATE_COMPONENT:
	case ui::INPUT_EVENT_LATENCY_TERMINATED_SWAP_FAILED_COMPONENT:
	return true;
	default:
	return false;
	}
	}

	bool IsBeginComponent(ui::LatencyComponentType type) {
	return (type == ui::INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT \|\|
	type == ui::LATENCY_BEGIN_SCROLL_LISTENER_UPDATE_MAIN_COMPONENT);
	}

	bool IsInputLatencyBeginComponent(ui::LatencyComponentType type) {
	return type == ui::INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT;
	}

	// This class is for converting latency info to trace buffer friendly format.
	class LatencyInfoTracedValue
	: public base::trace_event::ConvertableToTraceFormat {
	public:
	static std::unique_ptr<ConvertableToTraceFormat> FromValue(
	std::unique_ptr<base::Value> value);

	void AppendAsTraceFormat(std::string* out) const override;

	private:
	explicit LatencyInfoTracedValue(base::Value* value);
	~LatencyInfoTracedValue() override;

	std::unique_ptr<base::Value> value_;

	DISALLOW_COPY_AND_ASSIGN(LatencyInfoTracedValue);
	};

	std::unique_ptr<base::trace_event::ConvertableToTraceFormat>
	LatencyInfoTracedValue::FromValue(std::unique_ptr<base::Value> value) {
	return std::unique_ptr<base::trace_event::ConvertableToTraceFormat>(
	new LatencyInfoTracedValue(value.release()));
	}

	LatencyInfoTracedValue::~LatencyInfoTracedValue() {
	}

	void LatencyInfoTracedValue::AppendAsTraceFormat(std::string* out) const {
	std::string tmp;
	base::JSONWriter::Write(*value_, &tmp);
	*out += tmp;
	}

	LatencyInfoTracedValue::LatencyInfoTracedValue(base::Value* value)
	: value_(value) {
	}

	const char kTraceCategoriesForAsyncEvents[] = "benchmark,latencyInfo";

	struct LatencyInfoEnabledInitializer {
	LatencyInfoEnabledInitializer() :
	latency_info_enabled(TRACE_EVENT_API_GET_CATEGORY_GROUP_ENABLED(
	kTraceCategoriesForAsyncEvents)) {
	}

	const unsigned char* latency_info_enabled;
	};

	static base::LazyInstance<LatencyInfoEnabledInitializer>::Leaky
	g_latency_info_enabled = LAZY_INSTANCE_INITIALIZER;

	} // namespace

	namespace ui {

	LatencyInfo::InputCoordinate::InputCoordinate() : x(0), y(0) {
	}

	LatencyInfo::InputCoordinate::InputCoordinate(float x, float y) : x(x), y(y) {
	}

	LatencyInfo::LatencyInfo()
	: input_coordinates_size_(0),
	trace_id_(-1),
	coalesced_(false),
	terminated_(false) {}

	LatencyInfo::LatencyInfo(const LatencyInfo& other) = default;

	LatencyInfo::~LatencyInfo() {}

	LatencyInfo::LatencyInfo(int64_t trace_id, bool terminated)
	: input_coordinates_size_(0),
	trace_id_(trace_id),
	terminated_(terminated) {}

	bool LatencyInfo::Verify(const std::vector<LatencyInfo>& latency_info,
	const char* referring_msg) {
	if (latency_info.size() > kMaxLatencyInfoNumber) {
	LOG(ERROR) << referring_msg << ", LatencyInfo vector size "
	<< latency_info.size() << " is too big.";
	TRACE_EVENT_INSTANT1("input,benchmark", "LatencyInfo::Verify Fails",
	TRACE_EVENT_SCOPE_GLOBAL,
	"size", latency_info.size());
	return false;
	}
	return true;
	}

	void LatencyInfo::CopyLatencyFrom(const LatencyInfo& other,
	LatencyComponentType type) {
	for (const auto& lc : other.latency_components()) {
	if (lc.first.first == type) {
	AddLatencyNumberWithTimestamp(lc.first.first,
	lc.first.second,
	lc.second.sequence_number,
	lc.second.event_time,
	lc.second.event_count);
	}
	}
	}

	void LatencyInfo::AddNewLatencyFrom(const LatencyInfo& other) {
	for (const auto& lc : other.latency_components()) {
	if (!FindLatency(lc.first.first, lc.first.second, NULL)) {
	AddLatencyNumberWithTimestamp(lc.first.first,
	lc.first.second,
	lc.second.sequence_number,
	lc.second.event_time,
	lc.second.event_count);
	}
	}
	}

	void LatencyInfo::AddLatencyNumber(LatencyComponentType component,
	int64_t id,
	int64_t component_sequence_number) {
	AddLatencyNumberWithTimestampImpl(component, id, component_sequence_number,
	base::TimeTicks::Now(), 1, nullptr);
	}

	void LatencyInfo::AddLatencyNumberWithTraceName(
	LatencyComponentType component,
	int64_t id,
	int64_t component_sequence_number,
	const char* trace_name_str) {
	AddLatencyNumberWithTimestampImpl(component, id, component_sequence_number,
	base::TimeTicks::Now(), 1, trace_name_str);
	}

	void LatencyInfo::AddLatencyNumberWithTimestamp(
	LatencyComponentType component,
	int64_t id,
	int64_t component_sequence_number,
	base::TimeTicks time,
	uint32_t event_count) {
	AddLatencyNumberWithTimestampImpl(component, id, component_sequence_number,
	time, event_count, nullptr);
	}

	void LatencyInfo::AddLatencyNumberWithTimestampImpl(
	LatencyComponentType component,
	int64_t id,
	int64_t component_sequence_number,
	base::TimeTicks time,
	uint32_t event_count,
	const char* trace_name_str) {
	const unsigned char* latency_info_enabled =
	g_latency_info_enabled.Get().latency_info_enabled;

	if (IsBeginComponent(component)) {
	// Should only ever add begin component once.
	CHECK_EQ(-1, trace_id_);
	trace_id_ = component_sequence_number;

	if (*latency_info_enabled) {
	// The timestamp for ASYNC_BEGIN trace event is used for drawing the
	// beginning of the trace event in trace viewer. For better visualization,
	// for an input event, we want to draw the beginning as when the event is
	// originally created, e.g. the timestamp of its ORIGINAL/UI_COMPONENT,
	// not when we actually issue the ASYNC_BEGIN trace event.
	LatencyComponent begin_component;
	int64_t ts = 0;
	if (FindLatency(INPUT_EVENT_LATENCY_ORIGINAL_COMPONENT,
	0,
	&begin_component) \|\|
	FindLatency(INPUT_EVENT_LATENCY_UI_COMPONENT,
	0,
	&begin_component)) {
	ts = begin_component.event_time.ToInternalValue();
	} else {
	ts = base::TimeTicks::Now().ToInternalValue();
	}

	if (trace_name_str) {
	if (IsInputLatencyBeginComponent(component))
	trace_name_ = std::string("InputLatency::") + trace_name_str;
	else
	trace_name_ = std::string("Latency::") + trace_name_str;
	}

	TRACE_EVENT_COPY_ASYNC_BEGIN_WITH_TIMESTAMP0(
	kTraceCategoriesForAsyncEvents,
	trace_name_.c_str(),
	TRACE_ID_DONT_MANGLE(trace_id_),
	ts);
	}

	TRACE_EVENT_WITH_FLOW1("input,benchmark",
	"LatencyInfo.Flow",
	TRACE_ID_DONT_MANGLE(trace_id_),
	TRACE_EVENT_FLAG_FLOW_OUT,
	"trace_id", trace_id_);
	}

	LatencyMap::key_type key = std::make_pair(component, id);
	LatencyMap::iterator it = latency_components_.find(key);
	if (it == latency_components_.end()) {
	LatencyComponent info = {component_sequence_number, time, event_count};
	latency_components_[key] = info;
	} else {
	it->second.sequence_number = std::max(component_sequence_number,
	it->second.sequence_number);
	uint32_t new_count = event_count + it->second.event_count;
	if (event_count > 0 && new_count != 0) {
	// Do a weighted average, so that the new event_time is the average of
	// the times of events currently in this structure with the time passed
	// into this method.
	it->second.event_time += (time - it->second.event_time) * event_count /
	new_count;
	it->second.event_count = new_count;
	}
	}

	if (IsTerminalComponent(component) && trace_id_ != -1) {
	// Should only ever add terminal component once.
	CHECK(!terminated_);
	terminated_ = true;

	if (*latency_info_enabled) {
	TRACE_EVENT_COPY_ASYNC_END2(kTraceCategoriesForAsyncEvents,
	trace_name_.c_str(),
	TRACE_ID_DONT_MANGLE(trace_id_),
	"data", AsTraceableData(),
	"coordinates", CoordinatesAsTraceableData());
	}

	TRACE_EVENT_WITH_FLOW0("input,benchmark",
	"LatencyInfo.Flow",
	TRACE_ID_DONT_MANGLE(trace_id_),
	TRACE_EVENT_FLAG_FLOW_IN);
	}
	}

	std::unique_ptr<base::trace_event::ConvertableToTraceFormat>
	LatencyInfo::AsTraceableData() {
	std::unique_ptr<base::DictionaryValue> record_data(
	new base::DictionaryValue());
	for (const auto& lc : latency_components_) {
	std::unique_ptr<base::DictionaryValue> component_info(
	new base::DictionaryValue());
	component_info->SetDouble("comp_id", static_cast<double>(lc.first.second));
	component_info->SetDouble(
	"time",
	static_cast<double>(lc.second.event_time.ToInternalValue()));
	component_info->SetDouble("count", lc.second.event_count);
	component_info->SetDouble("sequence_number",
	lc.second.sequence_number);
	record_data->Set(GetComponentName(lc.first.first),
	std::move(component_info));
	}
	record_data->SetDouble("trace_id", static_cast<double>(trace_id_));
	return LatencyInfoTracedValue::FromValue(std::move(record_data));
	}

	std::unique_ptr<base::trace_event::ConvertableToTraceFormat>
	LatencyInfo::CoordinatesAsTraceableData() {
	std::unique_ptr<base::ListValue> coordinates(new base::ListValue());
	for (size_t i = 0; i < input_coordinates_size_; i++) {
	std::unique_ptr<base::DictionaryValue> coordinate_pair(
	new base::DictionaryValue());
	coordinate_pair->SetDouble("x", input_coordinates_[i].x);
	coordinate_pair->SetDouble("y", input_coordinates_[i].y);
	coordinates->Append(coordinate_pair.release());
	}
	return LatencyInfoTracedValue::FromValue(std::move(coordinates));
	}

	bool LatencyInfo::FindLatency(LatencyComponentType type,
	int64_t id,
	LatencyComponent* output) const {
	LatencyMap::const_iterator it = latency_components_.find(
	std::make_pair(type, id));
	if (it == latency_components_.end())
	return false;
	if (output)
	*output = it->second;
	return true;
	}

	void LatencyInfo::RemoveLatency(LatencyComponentType type) {
	LatencyMap::iterator it = latency_components_.begin();
	while (it != latency_components_.end()) {
	if (it->first.first == type) {
	LatencyMap::iterator tmp = it;
	++it;
	latency_components_.erase(tmp);
	} else {
	it++;
	}
	}
	}

	bool LatencyInfo::AddInputCoordinate(const InputCoordinate& input_coordinate) {
	if (input_coordinates_size_ >= kMaxInputCoordinates)
	return false;
	input_coordinates_[input_coordinates_size_++] = input_coordinate;
	return true;
	}

	} // namespace ui