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

services/media/framework/stages/output.h

Index: services/media/framework/stages/output.h
diff --git a/services/media/framework/stages/output.h b/services/media/framework/stages/output.h
new file mode 100644
index 0000000000000000000000000000000000000000..4cebeb57b7c75406154b39d9fb7ecc7e28d5c264
--- /dev/null
+++ b/services/media/framework/stages/output.h
@@ -0,0 +1,68 @@
+// 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_OUTPUT_H_
+#define SERVICES_MEDIA_FRAMEWORK_STAGES_OUTPUT_H_
+
+#include "services/media/framework/packet.h"
+#include "services/media/framework/payload_allocator.h"
+#include "services/media/framework/refs.h"
+
+namespace mojo {
+namespace media {
+
+class Stage;
+class Engine;
+class Input;
+
+// Represents a stage's connector to an adjacent downstream stage.
+class Output {
+ public:
+  Output();
+
+  ~Output();
+
+  // The input to which this output is connected.
+  const InputRef& mate() const { return mate_; }
+
+  // Establishes a connection.
+  void Connect(const InputRef& input);
+
+  // Breaks a connection. Called only by the engine.
+  void Disconnect() { mate_ = nullptr; }
+
+  // Determines whether the output is connected to an input.
+  bool connected() const { return static_cast<bool>(mate_); }
+
+  // The connected input.
+  Input& actual_mate() const;
+
+  // Sets the allocator the output must use to copy the payload of output
+  // packets. This is used when the connected input insists that a specific
+  // allocator be used, but the stage can't use it.
+  void SetCopyAllocator(PayloadAllocator* copy_allocator);
+
+  // Demand signalled from downstream, or kNegative if the downstream input
+  // is currently holding a packet.
+  Demand demand() const;
+
+  // Supplies a packet to mate. Called only by Stage::Update implementations.
+  void SupplyPacket(PacketPtr packet, Engine* engine) const;
+
+  // Updates packet demand. Called only by Input instances.
+  bool UpdateDemandFromInput(Demand demand);
+
+  // Flushes retained media.
+  void Flush();
+
+ private:
+  InputRef mate_;
+  Demand demand_;
+  PayloadAllocator* copy_allocator_;
+};
+
+}  // namespace media
+}  // namespace mojo
+
+#endif  // SERVICES_MEDIA_FRAMEWORK_STAGES_OUTPUT_H_