Generate and assign media track ids in demuxers.

media/filters/frame_processor_unittest.cc

Index: media/filters/frame_processor_unittest.cc
diff --git a/media/filters/frame_processor_unittest.cc b/media/filters/frame_processor_unittest.cc
index d226e91d7a3e77618b95d54a437cdff3333ec402..6b3fce21106af77a688180e177e4f687236cdd4b 100644
--- a/media/filters/frame_processor_unittest.cc
+++ b/media/filters/frame_processor_unittest.cc
@@ -291,7 +291,7 @@ class FrameProcessorTest : public testing::TestWithParam<bool> {
     switch (type) {
       case DemuxerStream::AUDIO: {
         ASSERT_FALSE(audio_);
-        audio_.reset(new ChunkDemuxerStream(DemuxerStream::AUDIO, true));
+        audio_.reset(new ChunkDemuxerStream(DemuxerStream::AUDIO, true, "1"));
         AudioDecoderConfig decoder_config(kCodecVorbis, kSampleFormatPlanarF32,
                                           CHANNEL_LAYOUT_STEREO, 1000,
                                           EmptyExtraData(), Unencrypted());
@@ -301,7 +301,7 @@ class FrameProcessorTest : public testing::TestWithParam<bool> {
       }
       case DemuxerStream::VIDEO: {
         ASSERT_FALSE(video_);
-        video_.reset(new ChunkDemuxerStream(DemuxerStream::VIDEO, true));
+        video_.reset(new ChunkDemuxerStream(DemuxerStream::VIDEO, true, "2"));
         ASSERT_TRUE(video_->UpdateVideoConfig(TestVideoConfig::Normal(),
                                               new MediaLog()));
         break;