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

services/media/framework/stages/active_multistream_sink_stage.h

Index: services/media/framework/stages/active_multistream_sink_stage.h
diff --git a/services/media/framework/stages/active_multistream_sink_stage.h b/services/media/framework/stages/active_multistream_sink_stage.h
new file mode 100644
index 0000000000000000000000000000000000000000..53cb6cd1f4e6383211223d539df381ee73bac125
--- /dev/null
+++ b/services/media/framework/stages/active_multistream_sink_stage.h
@@ -0,0 +1,84 @@
+// 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_ACTIVE_MULTISTREAM_SINK_STAGE_H_
+#define SERVICES_MEDIA_FRAMEWORK_STAGES_ACTIVE_MULTISTREAM_SINK_STAGE_H_
+
+#include <list>
+#include <set>
+#include <vector>
+
+#include "base/synchronization/lock.h"
+#include "services/media/framework/models/active_multistream_sink.h"
+#include "services/media/framework/stages/stage.h"
+
+namespace mojo {
+namespace media {
+
+// A stage that hosts an ActiveSink.
+class ActiveMultistreamSinkStage :
+    public Stage,
+    public ActiveMultistreamSinkHost {
+ public:
+  ActiveMultistreamSinkStage(std::shared_ptr<ActiveMultistreamSink> sink);
+
+  ~ActiveMultistreamSinkStage() 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 Prime() override;
+
+  void Update(Engine* engine) override;
+
+  void FlushInput(
+      size_t index,
+      const DownstreamCallback& callback) override;
+
+  void FlushOutput(size_t index) override;
+
+  // ActiveMultistreamSinkHost implementation.
+  size_t AllocateInput() override;
+
+  size_t ReleaseInput(size_t index) override;
+
+  void UpdateDemand(size_t input_index, Demand demand) override;
+
+ private:
+  struct StageInput {
+    StageInput(size_t index) :
+        index_(index),
+        allocated_(false),
+        demand_(Demand::kNegative) {}
+    Input input_;
+    size_t index_;
+    bool allocated_;
+    Demand demand_;
+  };
+
+  std::shared_ptr<ActiveMultistreamSink> sink_;
+
+  mutable base::Lock lock_;
+  std::vector<std::unique_ptr<StageInput>> inputs_;
+  std::set<size_t> unallocated_inputs_;
+  std::list<size_t> pending_inputs_;
+};
+
+}  // namespace media
+}  // namespace mojo
+
+#endif  // SERVICES_MEDIA_FRAMEWORK_STAGES_ACTIVE_MULTISTREAM_SINK_STAGE_H_