gpu: Add a class MeasurementTimers that measures wall, cpu and gpu time.

gpu/perftests/measurements.h

+// 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 GPU_PERFTESTS_MEASUREMENTS_H_
+#define GPU_PERFTESTS_MEASUREMENTS_H_
+
+#include <string>
+
+#include "base/time/time.h"
+#include "base/timer/elapsed_timer.h"
+#include "ui/gl/gl_bindings.h"
+
+namespace gpu {
+
+struct Measurement {
+  Measurement();
+  Measurement(const Measurement& m);
+  Measurement(const std::string& name,
+              const base::TimeDelta wall_time,
+              const base::TimeDelta cpu_time,
+              const base::TimeDelta gpu_time);
+  ~Measurement();
+
+  void PrintResult() const;
+  Measurement& Increment(const Measurement& m);
+  Measurement Divide(int a) const;
+
+  std::string name;
+  base::TimeDelta wall_time;
+  base::TimeDelta cpu_time;
+  base::TimeDelta gpu_time;
+};
+
+// Class to measure wall, cpu and gpu time deltas.
+// The deltas are measured from the time of the object
+// creation up to when Record is called.
+class MeasurementTimers {
+ public:
+  MeasurementTimers();
+  void Record();
+  Measurement GetAsMeasurement(const std::string& name);
+  ~MeasurementTimers();
+
+ private:
+  base::ElapsedTimer wall_timer_;

[piman, 2015/01/30 21:12:04]

ElapsedTimer uses TimeTicks::Now which can have low resolution on Windows.
Should we use TimeTicks::NowFromSystemTraceTime() which is high resolution?

[Daniele Castagna, 2015/02/03 04:12:59]

Done.

+  base::TimeTicks cpu_time_begin_;
+  GLuint gl_queries_[2];
+
+  base::TimeDelta wall_time_;
+  base::TimeDelta cpu_time_;
+};
+
+}  // namespace gpu
+
+#endif  // GPU_PERFTESTS_MEASUREMENTS_H_