Allow media track switching.

media/renderers/default_renderer_factory.h

 // Copyright 2014 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 MEDIA_RENDERERS_DEFAULT_RENDERER_FACTORY_H_
 #define MEDIA_RENDERERS_DEFAULT_RENDERER_FACTORY_H_
 
 #include <memory>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/scoped_vector.h"
 #include "media/base/media_export.h"
 #include "media/base/renderer_factory.h"
 
 namespace media {
 
 class AudioDecoder;
 class AudioRendererSink;
 class DecoderFactory;
 class GpuVideoAcceleratorFactories;
 class MediaLog;
 class VideoDecoder;
 class VideoRendererSink;
 
+using CreateAudioDecodersCB = base::Callback<ScopedVector<AudioDecoder>()>;
+using CreateVideoDecodersCB = base::Callback<ScopedVector<VideoDecoder>()>;

[xhwang, 2017/03/27 19:13:53]

nit: Maybe use RepeatingCallback to make it clear this can be used repeatedly?

https://cs.chromium.org/chromium/src/docs/callback.md?rcl=2fc3ba8587526eb5e5f...

[servolk, 2017/03/27 22:34:13]

Done.

+
 // The default factory class for creating RendererImpl.
 class MEDIA_EXPORT DefaultRendererFactory : public RendererFactory {
  public:
   using GetGpuFactoriesCB = base::Callback<GpuVideoAcceleratorFactories*()>;
 
   DefaultRendererFactory(const scoped_refptr<MediaLog>& media_log,
                          DecoderFactory* decoder_factory,
                          const GetGpuFactoriesCB& get_gpu_factories_cb);
   ~DefaultRendererFactory() final;
 
@@ skipping 20 matching lines @@
 
   // Creates factories for supporting video accelerators. May be null.
   GetGpuFactoriesCB get_gpu_factories_cb_;
 
   DISALLOW_COPY_AND_ASSIGN(DefaultRendererFactory);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_RENDERERS_DEFAULT_RENDERER_FACTORY_H_