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

services/media/framework/stages/input.h

Index: services/media/framework/stages/input.h
diff --git a/services/media/framework/stages/input.h b/services/media/framework/stages/input.h
new file mode 100644
index 0000000000000000000000000000000000000000..2693a0e8850babbba3ac6a0ae5922125492b0a0c
--- /dev/null
+++ b/services/media/framework/stages/input.h
@@ -0,0 +1,73 @@
+// 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_INPUT_H_
+#define SERVICES_MEDIA_FRAMEWORK_STAGES_INPUT_H_
+
+#include "services/media/framework/models/demand.h"
+#include "services/media/framework/packet.h"
+#include "services/media/framework/refs.h"
+
+namespace mojo {
+namespace media {
+
+class Stage;
+class Engine;
+class Output;
+
+// Represents a stage's connector to an adjacent upstream stage.
+class Input {
+ public:
+  Input();
+
+  ~Input();
+
+  // The output to which this input is connected.
+  const OutputRef& mate() const { return mate_; }
+
+  // Establishes a connection.
+  void Connect(const OutputRef& output);
+
+  // Breaks a connection. Called only by the engine.
+  void Disconnect() {
+    DCHECK(!prepared_);
+    mate_ = nullptr;
+  }
+
+  // Determines whether the input is connected to an output.
+  bool connected() const { return static_cast<bool>(mate_); }
+
+  // The connected output.
+  Output& actual_mate() const;
+
+  // Determines if the input is prepared.
+  bool prepared() { return prepared_; }
+
+  // Changes the prepared state of the input.
+  void set_prepared(bool prepared) { prepared_ = prepared; }
+
+  // A packet supplied from upstream.
+  PacketPtr& packet_from_upstream() { return packet_from_upstream_; }
+
+  // Updates mate's demand. Called only by Stage::Update implementations.
+  void SetDemand(Demand demand, Engine* engine) const;
+
+  // Updates packet_from_upstream. Return value indicates whether the stage for
+  // this input should be added to the supply backlog. Called only by
+  // Output instances.
+  bool SupplyPacketFromOutput(PacketPtr packet);
+
+  // Flushes retained media.
+  void Flush();
+
+ private:
+  OutputRef mate_;
+  bool prepared_;
+  PacketPtr packet_from_upstream_;
+};
+
+}  // namespace media
+}  // namespace mojo
+
+#endif  // SERVICES_MEDIA_FRAMEWORK_STAGES_INPUT_H_