Fix playback rate calculations for WallClockTimeSource.

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_));
+    AdvanceTimeInSeconds(1);
   }
   ~WallClockTimeSourceTest() override {}
 
   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));
   }
 
+  bool IsWallClockNowForMediaTimeInSeconds(int seconds) {

[xhwang, 2015/04/15 04:22:57]

This naming is hard to read. But I don't have better suggestions...

[DaleCurtis, 2015/04/15 18:42:28]

Yeah, it's a bit wordy, but explicit :) I've cleaned up the names a little bit.

+    return tick_clock_->NowTicks() ==
+           time_source_.GetWallClockTime(base::TimeDelta::FromSeconds(seconds));
+  }
+
+  bool IsWallClockTimeNullForMediaTimeInSeconds(int seconds) {
+    return base::TimeTicks() ==
+           time_source_.GetWallClockTime(base::TimeDelta::FromSeconds(seconds));
+  }
+
+ protected:
   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());
+  EXPECT_TRUE(IsWallClockTimeNullForMediaTimeInSeconds(0));
 }
 
 TEST_F(WallClockTimeSourceTest, InitialTimeIsNotTicking) {
   EXPECT_EQ(0, CurrentMediaTimeInSeconds());
+  EXPECT_TRUE(IsWallClockTimeNullForMediaTimeInSeconds(0));
   AdvanceTimeInSeconds(100);
   EXPECT_EQ(0, CurrentMediaTimeInSeconds());
+  EXPECT_TRUE(IsWallClockTimeNullForMediaTimeInSeconds(0));
 }
 
 TEST_F(WallClockTimeSourceTest, InitialPlaybackRateIsOne) {
   time_source_.StartTicking();
 
   EXPECT_EQ(0, CurrentMediaTimeInSeconds());
+  EXPECT_TRUE(IsWallClockNowForMediaTimeInSeconds(0));
   AdvanceTimeInSeconds(100);
   EXPECT_EQ(100, CurrentMediaTimeInSeconds());
+  EXPECT_TRUE(IsWallClockNowForMediaTimeInSeconds(100));
 }
 
 TEST_F(WallClockTimeSourceTest, SetMediaTime) {
   EXPECT_EQ(0, CurrentMediaTimeInSeconds());
+  EXPECT_TRUE(IsWallClockTimeNullForMediaTimeInSeconds(0));
   SetMediaTimeInSeconds(10);
   EXPECT_EQ(10, CurrentMediaTimeInSeconds());
+  EXPECT_TRUE(IsWallClockTimeNullForMediaTimeInSeconds(10));
 }
 
 TEST_F(WallClockTimeSourceTest, SetPlaybackRate) {
   time_source_.StartTicking();
 
   time_source_.SetPlaybackRate(0.5);
   EXPECT_EQ(0, CurrentMediaTimeInSeconds());
+  EXPECT_TRUE(IsWallClockNowForMediaTimeInSeconds(0));
   AdvanceTimeInSeconds(10);
   EXPECT_EQ(5, CurrentMediaTimeInSeconds());
+  EXPECT_TRUE(IsWallClockNowForMediaTimeInSeconds(5));
 
   time_source_.SetPlaybackRate(2);
   EXPECT_EQ(5, CurrentMediaTimeInSeconds());
+  EXPECT_TRUE(IsWallClockNowForMediaTimeInSeconds(5));
   AdvanceTimeInSeconds(10);
   EXPECT_EQ(25, CurrentMediaTimeInSeconds());
+  EXPECT_TRUE(IsWallClockNowForMediaTimeInSeconds(25));
 }
 
 TEST_F(WallClockTimeSourceTest, StopTicking) {
   time_source_.StartTicking();
 
   EXPECT_EQ(0, CurrentMediaTimeInSeconds());
+  EXPECT_TRUE(IsWallClockNowForMediaTimeInSeconds(0));
   AdvanceTimeInSeconds(10);
   EXPECT_EQ(10, CurrentMediaTimeInSeconds());
+  EXPECT_TRUE(IsWallClockNowForMediaTimeInSeconds(10));
 
   time_source_.StopTicking();
 
   AdvanceTimeInSeconds(10);
   EXPECT_EQ(10, CurrentMediaTimeInSeconds());
+  EXPECT_TRUE(IsWallClockTimeNullForMediaTimeInSeconds(10));
 }
 
 }  // namespace media