Add VideoCodec::PreferDecodeLate

webrtc/video_decoder.h

Index: webrtc/video_decoder.h
diff --git a/webrtc/video_decoder.h b/webrtc/video_decoder.h
index 2822677868db4f3aa531e1e7bd4bf3c2dc6ff176..7ee6688784f00f9749d2b6ce1516e0750117849d 100644
--- a/webrtc/video_decoder.h
+++ b/webrtc/video_decoder.h
@@ -63,6 +63,13 @@ class VideoDecoder {
 
   virtual int32_t Release() = 0;
   virtual int32_t Reset() = 0;
+
+  // Returns true if the currently active decoder only have one output buffer.

[perkj_webrtc, 2015/11/05 11:56:37]

has

+  // That means that frames must be decoded near the render times stamp since
+  // multiple frames can not be decoded ahead of time.
+  virtual bool HasOnlyOneOutputBuffer() const {

[pbos-webrtc, 2015/11/05 17:47:30]

I would like us to decode the extra output buffer as soon as it's available, was
that impossible to wire up?

+    return false;
+  }
 };
 
 // Class used to wrap external VideoDecoders to provide a fallback option on
@@ -87,6 +94,7 @@ class VideoDecoderSoftwareFallbackWrapper : public webrtc::VideoDecoder {
 
   int32_t Release() override;
   int32_t Reset() override;
+  bool HasOnlyOneOutputBuffer() const override;
 
  private:
   bool InitFallbackDecoder();