MediaResource refactoring to support multiple streams

chromecast/media/service/cast_renderer.cc

Index: chromecast/media/service/cast_renderer.cc
diff --git a/chromecast/media/service/cast_renderer.cc b/chromecast/media/service/cast_renderer.cc
index aa3ae067644ddc8c5fcbbe77667e5a653c156fe4..109517b2bc3f12a4ae30fd527de23dd9ffa65d2d 100644
--- a/chromecast/media/service/cast_renderer.cc
+++ b/chromecast/media/service/cast_renderer.cc
@@ -18,8 +18,8 @@
 #include "chromecast/public/media/media_pipeline_device_params.h"
 #include "media/base/audio_decoder_config.h"
 #include "media/base/demuxer_stream.h"
-#include "media/base/demuxer_stream_provider.h"
 #include "media/base/media_log.h"
+#include "media/base/media_resource.h"
 #include "media/base/renderer_client.h"
 
 namespace chromecast {
@@ -61,10 +61,9 @@ CastRenderer::~CastRenderer() {
     video_resolution_policy_->RemoveObserver(this);
 }
 
-void CastRenderer::Initialize(
-    ::media::DemuxerStreamProvider* demuxer_stream_provider,
-    ::media::RendererClient* client,
-    const ::media::PipelineStatusCB& init_cb) {
+void CastRenderer::Initialize(::media::MediaResource* media_resource,
+                              ::media::RendererClient* client,
+                              const ::media::PipelineStatusCB& init_cb) {
   CMALOG(kLogControl) << __FUNCTION__ << ": " << this;
   DCHECK(task_runner_->BelongsToCurrentThread());
 
@@ -92,9 +91,22 @@ void CastRenderer::Initialize(
   pipeline_->SetClient(pipeline_client);
   pipeline_->Initialize(load_type, std::move(backend));
 
+  // Obtain the first enabled audio and video streams.
+  std::vector<::media::DemuxerStream*> streams = media_resource->GetStreams();
+  ::media::DemuxerStream* audio_stream = nullptr;
+  ::media::DemuxerStream* video_stream = nullptr;
+  for (const auto& s : streams) {
+    if (!audio_stream && s->enabled() &&
+        s->type() == ::media::DemuxerStream::AUDIO) {
+      audio_stream = s;
+    }
+    if (!video_stream && s->enabled() &&
+        s->type() == ::media::DemuxerStream::VIDEO) {
+      video_stream = s;
+    }
+  }
+
   // Initialize audio.
-  ::media::DemuxerStream* audio_stream =
-      demuxer_stream_provider->GetStream(::media::DemuxerStream::AUDIO);
   if (audio_stream) {
     AvPipelineClient audio_client;
     audio_client.wait_for_key_cb = base::Bind(
@@ -119,8 +131,6 @@ void CastRenderer::Initialize(
   }
 
   // Initialize video.
-  ::media::DemuxerStream* video_stream =
-      demuxer_stream_provider->GetStream(::media::DemuxerStream::VIDEO);
   if (video_stream) {
     VideoPipelineClient video_client;
     video_client.av_pipeline_client.wait_for_key_cb = base::Bind(