Introduce media::TimeSource.

media/base/wall_clock_time_source_unittest.cc

+// Copyright 2014 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/test/simple_test_tick_clock.h"
+#include "media/base/wall_clock_time_source.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace media {
+
+class WallClockTimeSourceTest : public testing::Test {
+ public:
+  WallClockTimeSourceTest() : tick_clock_(new base::SimpleTestTickClock()) {
+    time_source_.SetTickClockForTesting(
+        scoped_ptr<base::TickClock>(tick_clock_));
+  }
+  virtual ~WallClockTimeSourceTest() {}
+
+  void AdvanceTimeInSeconds(int seconds) {
+    tick_clock_->Advance(base::TimeDelta::FromSeconds(seconds));
+  }
+
+  int CurrentMediaTimeInSeconds() {
+    return time_source_.CurrentMediaTime().InSeconds();
+  }
+
+  void SetMediaTimeInSeconds(int seconds) {
+    return time_source_.SetMediaTime(base::TimeDelta::FromSeconds(seconds));
+  }
+
+  WallClockTimeSource time_source_;
+
+ private:
+  base::SimpleTestTickClock* tick_clock_;  // Owned by |time_source_|.
+
+  DISALLOW_COPY_AND_ASSIGN(WallClockTimeSourceTest);
+};
+
+TEST_F(WallClockTimeSourceTest, InitialTimeIsZero) {
+  EXPECT_EQ(0, CurrentMediaTimeInSeconds());
+}
+
+TEST_F(WallClockTimeSourceTest, InitialTimeIsNotTicking) {
+  EXPECT_EQ(0, CurrentMediaTimeInSeconds());
+  AdvanceTimeInSeconds(100);
+  EXPECT_EQ(0, CurrentMediaTimeInSeconds());
+}
+
+TEST_F(WallClockTimeSourceTest, InitialPlaybackRateIsOne) {
+  time_source_.StartTicking();
+
+  EXPECT_EQ(0, CurrentMediaTimeInSeconds());
+  AdvanceTimeInSeconds(100);
+  EXPECT_EQ(100, CurrentMediaTimeInSeconds());
+}
+
+TEST_F(WallClockTimeSourceTest, SetMediaTime) {
+  EXPECT_EQ(0, CurrentMediaTimeInSeconds());
+  SetMediaTimeInSeconds(10);
+  EXPECT_EQ(10, CurrentMediaTimeInSeconds());
+}
+
+TEST_F(WallClockTimeSourceTest, SetPlaybackRate) {
+  time_source_.StartTicking();
+
+  time_source_.SetPlaybackRate(0.5);
+  EXPECT_EQ(0, CurrentMediaTimeInSeconds());
+  AdvanceTimeInSeconds(10);
+  EXPECT_EQ(5, CurrentMediaTimeInSeconds());
+
+  time_source_.SetPlaybackRate(2);
+  EXPECT_EQ(5, CurrentMediaTimeInSeconds());
+  AdvanceTimeInSeconds(10);
+  EXPECT_EQ(25, CurrentMediaTimeInSeconds());
+}
+
+TEST_F(WallClockTimeSourceTest, StopTicking) {
+  time_source_.StartTicking();
+
+  EXPECT_EQ(0, CurrentMediaTimeInSeconds());
+  AdvanceTimeInSeconds(10);
+  EXPECT_EQ(10, CurrentMediaTimeInSeconds());
+
+  time_source_.StopTicking();
+
+  AdvanceTimeInSeconds(10);
+  EXPECT_EQ(10, CurrentMediaTimeInSeconds());
+}
+
+}  // namespace media