Motown: Add ActiveMultistreamSource model in preparation for the ffmpeg demux with async I/O

services/media/framework/stages/active_multistream_source_stage.h

Index: services/media/framework/stages/active_multistream_source_stage.h
diff --git a/services/media/framework/stages/multistream_source_stage.h b/services/media/framework/stages/active_multistream_source_stage.h
similarity index 61%
copy from services/media/framework/stages/multistream_source_stage.h
copy to services/media/framework/stages/active_multistream_source_stage.h
index d3b2aea94bb5bc9019a0d9ea94881f76c7bec58f..625c4e3f3d07c7147b6ce5f35900934a597ae30f 100644
--- a/services/media/framework/stages/multistream_source_stage.h
+++ b/services/media/framework/stages/active_multistream_source_stage.h
@@ -2,24 +2,23 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef SERVICES_MEDIA_FRAMEWORK_STAGES_MULTISTREAM_SOURCE_STAGE_H_
-#define SERVICES_MEDIA_FRAMEWORK_STAGES_MULTISTREAM_SOURCE_STAGE_H_
+#ifndef SERVICES_MEDIA_FRAMEWORK_STAGES_ACTIVE_MULTISTREAM_SOURCE_STAGE_H_
+#define SERVICES_MEDIA_FRAMEWORK_STAGES_ACTIVE_MULTISTREAM_SOURCE_STAGE_H_
 
 #include <vector>
 
-#include "services/media/framework/models/multistream_source.h"
+#include "services/media/framework/models/active_multistream_source.h"
 #include "services/media/framework/stages/stage.h"
 
 namespace mojo {
 namespace media {
 
-// A stage that hosts a MultistreamSource.
-// TODO(dalesat): May need to grow the list of outputs dynamically.
-class MultistreamSourceStage : public Stage {
+// A stage that hosts an ActiveMultistreamSource.
+class ActiveMultistreamSourceStage : public Stage {
  public:
-  MultistreamSourceStage(std::shared_ptr<MultistreamSource> source);
+  ActiveMultistreamSourceStage(std::shared_ptr<ActiveMultistreamSource> source);
 
-  ~MultistreamSourceStage() override;
+  ~ActiveMultistreamSourceStage() override;
 
   // Stage implementation.
   size_t input_count() const override;
@@ -46,13 +45,14 @@ class MultistreamSourceStage : public Stage {
 
  private:
   std::vector<Output> outputs_;
-  std::shared_ptr<MultistreamSource> source_;
+  std::shared_ptr<ActiveMultistreamSource> source_;
+  ActiveMultistreamSource::SupplyCallback supply_function_;
   PacketPtr cached_packet_;
   size_t cached_packet_output_index_;
-  size_t ended_streams_;
+  size_t ended_streams_ = 0;
 };
 
 }  // namespace media
 }  // namespace mojo
 
-#endif  // SERVICES_MEDIA_FRAMEWORK_STAGES_MULTISTREAM_SOURCE_STAGE_H_
+#endif  // SERVICES_MEDIA_FRAMEWORK_STAGES_ACTIVE_MULTISTREAM_SOURCE_STAGE_H_