Move VideoRenderer out of Filter heirarchy.

media/base/filters.h

-// Copyright (c) 2012 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.
-
-// Filters are connected in a strongly typed manner, with downstream filters
-// always reading data from upstream filters.  Upstream filters have no clue
-// who is actually reading from them, and return the results via callbacks.
-//
-//                         DemuxerStream(Video) <- VideoDecoder <- VideoRenderer
-// DataSource <- Demuxer <
-//                         DemuxerStream(Audio) <- AudioDecoder <- AudioRenderer
-//
-// Upstream -------------------------------------------------------> Downstream
-//                         <- Reads flow this way
-//                    Buffer assignments flow this way ->
-//
-// Every filter maintains a reference to the scheduler, who maintains data
-// shared between filters (i.e., reference clock value, playback state).  The
-// scheduler is also responsible for scheduling filter tasks (i.e., a read on
-// a VideoDecoder would result in scheduling a Decode task).  Filters can also
-// use the scheduler to signal errors and shutdown playback.
-
-#ifndef MEDIA_BASE_FILTERS_H_
-#define MEDIA_BASE_FILTERS_H_
-
-#include "base/callback.h"
-#include "base/memory/ref_counted.h"
-#include "base/time.h"
-#include "media/base/media_export.h"
-#include "media/base/pipeline_status.h"
-
-namespace media {
-
-class FilterHost;
-
-class MEDIA_EXPORT Filter : public base::RefCountedThreadSafe<Filter> {
- public:
-  Filter();
-
-  // Sets the host that owns this filter. The host holds a strong
-  // reference to the filter.  The reference held by the host is guaranteed
-  // to be released before the host object is destroyed by the pipeline.
-  virtual void SetHost(FilterHost* host) = 0;
-
-  // The pipeline has resumed playback.  Filters can continue requesting reads.
-  // Filters may implement this method if they need to respond to this call.
-  virtual void Play(const base::Closure& callback) = 0;
-
-  // The pipeline has paused playback.  Filters should stop buffer exchange.
-  // Filters may implement this method if they need to respond to this call.
-  virtual void Pause(const base::Closure& callback) = 0;
-
-  // The pipeline has been flushed.  Filters should return buffer to owners.
-  // Filters may implement this method if they need to respond to this call.
-  virtual void Flush(const base::Closure& callback) = 0;
-
-  // The pipeline is being stopped either as a result of an error or because
-  // the client called Stop().
-  virtual void Stop(const base::Closure& callback) = 0;
-
-  // The pipeline playback rate has been changed.  Filters may implement this
-  // method if they need to respond to this call.
-  virtual void SetPlaybackRate(float playback_rate) = 0;
-
-  // Carry out any actions required to seek to the given time, executing the
-  // callback upon completion.
-  virtual void Seek(base::TimeDelta time, const PipelineStatusCB& callback) = 0;
-
- protected:
-  // Only allow scoped_refptr<> to delete filters.
-  friend class base::RefCountedThreadSafe<Filter>;
-  virtual ~Filter();
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(Filter);
-};
-
-}  // namespace media
-
-#endif  // MEDIA_BASE_FILTERS_H_