Trace-based benchmarking via a mojo app.

apps/benchmark/measurements.h

Index: apps/benchmark/measurements.h
diff --git a/apps/benchmark/measurements.h b/apps/benchmark/measurements.h
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+// Copyright 2015 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 APPS_BENCHMARK_MEASUREMENTS_HH_
+#define APPS_BENCHMARK_MEASUREMENTS_HH_
+
+#include <vector>
+
+#include "apps/benchmark/event.h"
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/time/time.h"
+#include "base/values.h"
+
+namespace benchmark {
+
+// Describes a trace event to match.
+struct EventSpec {
+  std::string name;
+  std::string category;
+
+  EventSpec();
+  EventSpec(std::string name, std::string category);
+  ~EventSpec();
+};
+
+enum class MeasurementType { TIME_UNTIL, AVG_DURATION };
+
+// Represents a single measurement to be performed on the collected trace.
+struct Measurement {
+  MeasurementType type;
+  EventSpec target_event;
+  // Optional string from which this measurement was parsed. Can be used for
+  // presentation purposes.
+  std::string spec;
+
+  Measurement();
+  Measurement(MeasurementType type,
+              std::string target_name,
+              std::string target_category);
+  ~Measurement();
+};
+
+class Measurements {
+ public:
+  Measurements(std::vector<Event> events, base::TimeTicks time_origin);
+  ~Measurements();
+
+  // Performs the given measurement. Returns the result in milliseconds or -1.0
+  // if the measurement failed, e.g. because no events were matched.
+  double Measure(const Measurement& measurement);
+
+ private:
+  double TimeUntil(const EventSpec& event_spec);
+  double AvgDuration(const EventSpec& event_spec);
+
+  std::vector<Event> events_;
+  base::TimeTicks time_origin_;
+  DISALLOW_COPY_AND_ASSIGN(Measurements);
+};
+
+}  // namespace benchmark
+
+#endif  // APPS_BENCHMARK_MEASUREMENTS_HH_