Refactor MediaResource to be multi-stream capable

media/base/pipeline_impl.cc

Index: media/base/pipeline_impl.cc
diff --git a/media/base/pipeline_impl.cc b/media/base/pipeline_impl.cc
index 0ec81f9e7ca815c345531ba3f35ce1779b93d393..3270fb26c60980a0e325807c425d4ebdd624be4f 100644
--- a/media/base/pipeline_impl.cc
+++ b/media/base/pipeline_impl.cc
@@ -860,8 +860,7 @@ void PipelineImpl::RendererWrapper::InitializeRenderer(
 
   switch (demuxer_->GetType()) {
     case MediaResource::Type::STREAM:
-      if (!demuxer_->GetStream(DemuxerStream::AUDIO) &&
-          !demuxer_->GetStream(DemuxerStream::VIDEO)) {
+      if (demuxer_->GetStreams().empty()) {
         DVLOG(1) << "Error: demuxer does not have an audio or a video stream.";
         done_cb.Run(PIPELINE_ERROR_COULD_NOT_RENDER);
         return;
@@ -901,24 +900,26 @@ void PipelineImpl::RendererWrapper::ReportMetadata() {
   DCHECK(media_task_runner_->BelongsToCurrentThread());
 
   PipelineMetadata metadata;
-  DemuxerStream* stream;
+  std::vector<DemuxerStream*> streams;
 
   switch (demuxer_->GetType()) {
     case MediaResource::Type::STREAM:
       metadata.timeline_offset = demuxer_->GetTimelineOffset();
-      stream = demuxer_->GetStream(DemuxerStream::VIDEO);
-      if (stream) {
-        metadata.has_video = true;
-        metadata.natural_size =
-            GetRotatedVideoSize(stream->video_rotation(),
-                                stream->video_decoder_config().natural_size());
-        metadata.video_rotation = stream->video_rotation();
-        metadata.video_decoder_config = stream->video_decoder_config();
-      }
-      stream = demuxer_->GetStream(DemuxerStream::AUDIO);
-      if (stream) {
-        metadata.has_audio = true;
-        metadata.audio_decoder_config = stream->audio_decoder_config();
+      // TODO(servolk): What should we do about metadata for multiple streams?
+      streams = demuxer_->GetStreams();
+      for (const auto& stream : streams) {
+        if (stream->type() == DemuxerStream::VIDEO && !metadata.has_video) {
+          metadata.has_video = true;
+          metadata.natural_size = GetRotatedVideoSize(
+              stream->video_rotation(),
+              stream->video_decoder_config().natural_size());
+          metadata.video_rotation = stream->video_rotation();
+          metadata.video_decoder_config = stream->video_decoder_config();
+        }
+        if (stream->type() == DemuxerStream::AUDIO && !metadata.has_audio) {
+          metadata.has_audio = true;
+          metadata.audio_decoder_config = stream->audio_decoder_config();
+        }
       }
       break;