Fix seeking when the start time is non-zero.

media/base/pipeline_unittest.cc

Index: media/base/pipeline_unittest.cc
diff --git a/media/base/pipeline_unittest.cc b/media/base/pipeline_unittest.cc
index 45cc73ba36fa7b1a46c5f19aed717b78da5be1fe..ecdad550f0309acf7ef576bb5c1354346d82d885 100644
--- a/media/base/pipeline_unittest.cc
+++ b/media/base/pipeline_unittest.cc
@@ -753,6 +753,9 @@ TEST_F(PipelineTest, StartTimeIsZero) {
   EXPECT_TRUE(metadata_.has_video);
 
   EXPECT_EQ(base::TimeDelta(), pipeline_->GetMediaTime());
+  const base::TimeDelta kSeekPoint = kDuration / 2;
+  ExpectSeek(kSeekPoint);
+  DoSeek(kSeekPoint);
 }
 
 TEST_F(PipelineTest, StartTimeIsNonZero) {
@@ -774,6 +777,34 @@ TEST_F(PipelineTest, StartTimeIsNonZero) {
   EXPECT_TRUE(metadata_.has_video);
 
   EXPECT_EQ(kStartTime, pipeline_->GetMediaTime());
+  const base::TimeDelta kSeekPoint = kDuration / 2;
+  ExpectSeek(kSeekPoint + kStartTime);
+  DoSeek(kSeekPoint);
+}
+
+TEST_F(PipelineTest, StartTimeIsNegative) {
+  const base::TimeDelta kStartTime = base::TimeDelta::FromSeconds(-4);
+  const base::TimeDelta kDuration = base::TimeDelta::FromSeconds(100);
+
+  EXPECT_CALL(*demuxer_, GetStartTime())
+      .WillRepeatedly(Return(kStartTime));
+
+  CreateVideoStream();
+  MockDemuxerStreamVector streams;
+  streams.push_back(video_stream());
+
+  InitializeDemuxer(&streams, kDuration);
+  InitializeVideoRenderer(video_stream());
+
+  InitializePipeline(PIPELINE_OK);
+  EXPECT_FALSE(metadata_.has_audio);
+  EXPECT_TRUE(metadata_.has_video);
+
+  // The media time should be clamped to zero.
+  EXPECT_EQ(base::TimeDelta(), pipeline_->GetMediaTime());
+  const base::TimeDelta kSeekPoint = kDuration / 2;
+  ExpectSeek(kSeekPoint + kStartTime);
+  DoSeek(kSeekPoint);
 }
 
 static void RunTimeCB(const AudioRenderer::TimeCB& time_cb,