Ensure media's buffered ranges always have a range that includes currentTime.

media/base/mock_demuxer_host.h

Index: media/base/mock_demuxer_host.h
diff --git a/media/base/mock_demuxer_host.h b/media/base/mock_demuxer_host.h
index dab553ac8655ff45404128b398ca446b05fc3c5f..597c13298c5e9d5520696c6936bff9ca41bbced0 100644
--- a/media/base/mock_demuxer_host.h
+++ b/media/base/mock_demuxer_host.h
@@ -20,6 +20,8 @@ class MockDemuxerHost : public DemuxerHost {
   // DataSourceHost implementation.
   MOCK_METHOD1(SetTotalBytes, void(int64 total_bytes));
   MOCK_METHOD2(AddBufferedByteRange, void(int64 start, int64 end));
+  MOCK_METHOD2(AddBufferedTimeRange, void(base::TimeDelta start,
+                                          base::TimeDelta end));
 
   // DemuxerHost implementation.
   MOCK_METHOD1(OnDemuxerError, void(PipelineStatus error));