gcc 4.6 warnings cleanup

media/filters/ffmpeg_demuxer_unittest.cc

Index: media/filters/ffmpeg_demuxer_unittest.cc
diff --git a/media/filters/ffmpeg_demuxer_unittest.cc b/media/filters/ffmpeg_demuxer_unittest.cc
index d5c76ae5592df31e7bfd16c3e3158e7a32df3883..9b62e2976876c7ae473420964df4c20c07c5cd3d 100644
--- a/media/filters/ffmpeg_demuxer_unittest.cc
+++ b/media/filters/ffmpeg_demuxer_unittest.cc
@@ -238,9 +238,6 @@ TEST_F(FFmpegDemuxerTest, Read_VideoNonZeroStart) {
   // Test the start time is the first timestamp of the video and audio stream.
   InitializeDemuxer(CreateDataSource("nonzero-start-time.webm"));
 
-  const base::TimeDelta kExpectedTimestamp =
-      base::TimeDelta::FromMicroseconds(396000);
-
   // Attempt a read from the video stream and run the message loop until done.
   scoped_refptr<DemuxerStream> video =
       demuxer_->GetStream(DemuxerStream::VIDEO);