Introduce cadence based VideoRendererAlgorithm.

media/base/moving_average_unittest.cc

+// 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.
+
+#include "base/time/time.h"
+#include "media/base/moving_average.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace media {
+
+TEST(MovingAverageTest, Average) {
+  const int kSamples = 5;
+  MovingAverage moving_average(kSamples);
+  moving_average.AddSample(base::TimeDelta::FromSeconds(1));
+  EXPECT_EQ(base::TimeDelta::FromSeconds(1), moving_average.Average());
+  for (int i = 0; i < kSamples - 1; ++i)
+    moving_average.AddSample(base::TimeDelta::FromSeconds(1));
+  EXPECT_EQ(base::TimeDelta::FromSeconds(1), moving_average.Average());
+
+  for (int i = 0; i < kSamples; ++i) {
+    moving_average.AddSample(base::TimeDelta::FromMilliseconds(500));
+    EXPECT_EQ(base::TimeDelta::FromMilliseconds(1000 - (i + 1) * 100),
+              moving_average.Average());
+  }
+}
+
+TEST(MovingAverageTest, Reset) {
+  MovingAverage moving_average(2);
+  moving_average.AddSample(base::TimeDelta::FromSeconds(1));
+  EXPECT_EQ(base::TimeDelta::FromSeconds(1), moving_average.Average());
+  moving_average.Reset();
+  moving_average.AddSample(base::TimeDelta());
+  EXPECT_EQ(base::TimeDelta(), moving_average.Average());
+}
+
+}  // namespace media