Change VideoSourceInterface::needs_denoising() to return rtc::Optional<bool>

webrtc/api/mediastreaminterface.h

 /*
  *  Copyright 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 // This file contains interfaces for MediaStream, MediaTrack and MediaSource.
 // These interfaces are used for implementing MediaStream and MediaTrack as
 // defined in http://dev.w3.org/2011/webrtc/editor/webrtc.html#stream-api. These
 // interfaces must be used only with PeerConnection. PeerConnectionManager
 // interface provides the factory methods to create MediaStream and MediaTracks.
 
 #ifndef WEBRTC_API_MEDIASTREAMINTERFACE_H_
 #define WEBRTC_API_MEDIASTREAMINTERFACE_H_
 
 #include <string>
 #include <vector>
 
 #include "webrtc/base/basictypes.h"
 #include "webrtc/base/refcount.h"
 #include "webrtc/base/scoped_ref_ptr.h"
+#include "webrtc/base/optional.h"
 #include "webrtc/media/base/mediachannel.h"
 #include "webrtc/media/base/videosinkinterface.h"
 #include "webrtc/media/base/videosourceinterface.h"
 
 namespace cricket {
 
 class AudioRenderer;
 class VideoCapturer;
 class VideoRenderer;
 class VideoFrame;
@@ skipping 84 matching lines @@
   // Indicates that parameters suitable for screencasts should be automatically
   // applied to RtpSenders.
   // TODO(perkj): Remove these once all known applications have moved to
   // explicitly setting suitable parameters for screencasts and dont' need this
   // implicit behavior.
   virtual bool is_screencast() const = 0;
 
   // Indicates that the encoder should denoise the video before encoding it.
   // TODO(perkj): Remove this once denoising is done by the source, and not by
   // the encoder.
-  virtual bool needs_denoising() const = 0;
+  virtual rtc::Optional<bool> needs_denoising() const = 0;

[pbos-webrtc, 2016/03/31 14:30:08]

Can we put a comment here on what unset means?

[perkj_webrtc, 2016/03/31 15:23:08]

Done.

 
  protected:
   virtual ~VideoTrackSourceInterface() {}
 };
 
 class VideoTrackInterface
     : public MediaStreamTrackInterface,
       public rtc::VideoSourceInterface<cricket::VideoFrame> {
  public:
   // Register a video sink for this track.
@@ skipping 124 matching lines @@
   virtual bool RemoveTrack(AudioTrackInterface* track) = 0;
   virtual bool RemoveTrack(VideoTrackInterface* track) = 0;
 
  protected:
   virtual ~MediaStreamInterface() {}
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_MEDIASTREAMINTERFACE_H_