Motown: Remove LPCM optimizations, fix prepare, add flush, add ActiveMultistreamSink model/stage

services/media/framework/stages/multistream_source_stage.h

Index: services/media/framework/stages/multistream_source_stage.h
diff --git a/services/media/framework/stages/multistream_source_stage.h b/services/media/framework/stages/multistream_source_stage.h
new file mode 100644
index 0000000000000000000000000000000000000000..d7af7a21fedcbb2113741d75dee7986020c5bb82
--- /dev/null
+++ b/services/media/framework/stages/multistream_source_stage.h
@@ -0,0 +1,63 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// 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_
+
+#include <vector>
+
+#include "services/media/framework/models/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 {
+ public:
+  MultistreamSourceStage(std::shared_ptr<MultistreamSource> source);
+
+  ~MultistreamSourceStage() override;
+
+  // Stage implementation.
+  size_t input_count() const override;
+
+  Input& input(size_t index) override;
+
+  size_t output_count() const override;
+
+  Output& output(size_t index) override;
+
+  PayloadAllocator* PrepareInput(size_t index) override;
+
+  void PrepareOutput(
+      size_t index,
+      PayloadAllocator* allocator,
+      const UpstreamCallback& callback) override;
+
+  void UnprepareOutput(
+      size_t index,
+      const UpstreamCallback& callback) override;
+
+  void Update(Engine* engine) override;
+
+  void FlushInput(
+      size_t index,
+      const DownstreamCallback& callback) override;
+
+  void FlushOutput(size_t index) override;
+
+ private:
+  std::vector<Output> outputs_;
+  std::shared_ptr<MultistreamSource> source_;
+  PacketPtr cached_packet_;
+  size_t cached_packet_output_index_;
+  size_t ended_streams_;
+};
+
+}  // namespace media
+}  // namespace mojo
+
+#endif  // SERVICES_MEDIA_FRAMEWORK_STAGES_MULTISTREAM_SOURCE_STAGE_H_