Unify media track info reporting on a demuxer level

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 a0611e9b5cfea3d247ffcdd22cff004d52e3e850..a6b82e22deab0cf3d0b9d31290fc4c7aa9141dae 100644
--- a/media/filters/ffmpeg_demuxer_unittest.cc
+++ b/media/filters/ffmpeg_demuxer_unittest.cc
@@ -17,6 +17,7 @@
 #include "base/threading/thread.h"
 #include "media/base/decrypt_config.h"
 #include "media/base/media_log.h"
+#include "media/base/media_tracks.h"
 #include "media/base/mock_demuxer_host.h"
 #include "media/base/test_helpers.h"
 #include "media/base/timestamp_constants.h"
@@ -91,9 +92,12 @@ class FFmpegDemuxerTest : public testing::Test {
     Demuxer::EncryptedMediaInitDataCB encrypted_media_init_data_cb = base::Bind(
         &FFmpegDemuxerTest::OnEncryptedMediaInitData, base::Unretained(this));
 
+    Demuxer::MediaTracksUpdatedCB tracks_updated_cb = base::Bind(
+        &FFmpegDemuxerTest::OnMediaTracksUpdated, base::Unretained(this));
+
     demuxer_.reset(new FFmpegDemuxer(
         message_loop_.task_runner(), data_source_.get(),
-        encrypted_media_init_data_cb, new MediaLog()));
+        encrypted_media_init_data_cb, tracks_updated_cb, new MediaLog()));
   }
 
   MOCK_METHOD1(CheckPoint, void(int v));
@@ -204,6 +208,8 @@ class FFmpegDemuxerTest : public testing::Test {
                void(EmeInitDataType init_data_type,
                     const std::vector<uint8_t>& init_data));
 
+  void OnMediaTracksUpdated(scoped_ptr<MediaTracks> tracks) {}

[wolenetz, 2016/03/05 01:47:43]

Now that we have this callback being exercised, seems a good time to also add
verification that expected track info (of at least some basic form) occurs.
wdyt?

[servolk, 2016/03/05 01:56:19]

Well, this CL doesn't yet include the changes to actually populate MediaTracks
object with any useful data. Check out the new unit tests in
https://codereview.chromium.org/1735003004/. I think the unit tests in that CL
should be enough to provide basic coverage of this functionality.

+
   // Accessor to demuxer internals.
   void set_duration_known(bool duration_known) {
     demuxer_->duration_known_ = duration_known;