Motown: Don't build out pipelines for streams that don't get rendered.

services/media/factory_service/media_sink_impl.h

 // 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 MOJO_SERVICES_MEDIA_FACTORY_MEDIA_SINK_IMPL_H_
 #define MOJO_SERVICES_MEDIA_FACTORY_MEDIA_SINK_IMPL_H_
 
 #include <memory>
 
 #include "mojo/public/cpp/bindings/binding.h"
@@ skipping 22 matching lines @@
 
   ~MediaSinkImpl() override;
 
   // MediaSink implementation.
   void GetConsumer(InterfaceRequest<MediaConsumer> consumer) override;
 
   void GetTimelineControlSite(
       InterfaceRequest<MediaTimelineControlSite> req) override;
 
  private:
-  class NullTimelineControlSite : public MediaTimelineControlSite,
-                                  public TimelineConsumer {
-   public:
-    NullTimelineControlSite(
-        InterfaceRequest<MediaTimelineControlSite> control_site_request);
-
-    ~NullTimelineControlSite() override;
-
-    // MediaTimelineControlSite implementation.
-    void GetStatus(uint64_t version_last_seen,
-                   const GetStatusCallback& callback) override;
-
-    void GetTimelineConsumer(
-        InterfaceRequest<TimelineConsumer> timeline_consumer) override;
-
-    // TimelineConsumer implementation.
-    void SetTimelineTransform(
-        int64_t subject_time,
-        uint32_t reference_delta,
-        uint32_t subject_delta,
-        int64_t effective_reference_time,
-        int64_t effective_subject_time,
-        const SetTimelineTransformCallback& callback) override;
-
-   private:
-    Binding<MediaTimelineControlSite> control_site_binding_;
-    Binding<TimelineConsumer> consumer_binding_;
-    GetStatusCallback get_status_callback_;
-  };
-
   MediaSinkImpl(InterfaceHandle<MediaRenderer> renderer,
                 MediaTypePtr media_type,
                 InterfaceRequest<MediaSink> request,
                 MediaFactoryService* owner);
 
   Incident ready_;
   Graph graph_;
   std::shared_ptr<MojoConsumer> consumer_;
   std::shared_ptr<MojoProducer> producer_;
   MediaRendererPtr renderer_;
   // The following fields are just temporaries used to solve lambda capture
   // problems.
   std::unique_ptr<StreamType> input_stream_type_;
 };
 
 }  // namespace media
 }  // namespace mojo
 
 #endif  // MOJO_SERVICES_MEDIA_FACTORY_MEDIA_SINK_IMPL_H_