ObjC: RTCVideoSource cleanup

webrtc/sdk/objc/Framework/Headers/WebRTC/RTCPeerConnectionFactory.h

 /*
  *  Copyright 2015 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.
  */
 
@@ skipping 28 matching lines @@
 - (RTCAudioTrack *)audioTrackWithTrackId:(NSString *)trackId;
 
 /** Initialize an RTCAudioTrack with a source and an id. */
 - (RTCAudioTrack *)audioTrackWithSource:(RTCAudioSource *)source
                                 trackId:(NSString *)trackId;
 
 /** Initialize an RTCAVFoundationVideoSource with constraints. */
 - (RTCAVFoundationVideoSource *)avFoundationVideoSourceWithConstraints:
     (nullable RTCMediaConstraints *)constraints;
 
+/** Initialize a generic RTCVideoSource. The RTCVideoSource should be passed to a RTCVideoCapturer
+ *  implementation, e.g. RTCCameraVideoCapturer, in order to produce frames.
+ */
 - (RTCVideoSource *)videoSource;
 
 /** Initialize an RTCVideoTrack with a source and an id. */
 - (RTCVideoTrack *)videoTrackWithSource:(RTCVideoSource *)source
                                 trackId:(NSString *)trackId;
 
 /** Initialize an RTCMediaStream with an id. */
 - (RTCMediaStream *)mediaStreamWithStreamId:(NSString *)streamId;
 
 /** Initialize an RTCPeerConnection with a configuration, constraints, and
  *  delegate.
  */
 - (RTCPeerConnection *)peerConnectionWithConfiguration:
     (RTCConfiguration *)configuration
                                            constraints:
     (RTCMediaConstraints *)constraints
                                               delegate:
     (nullable id<RTCPeerConnectionDelegate>)delegate;
 
 /** Start an AecDump recording. This API call will likely change in the future. */
 - (BOOL)startAecDumpWithFilePath:(NSString *)filePath
                   maxSizeInBytes:(int64_t)maxSizeInBytes;
 
 /* Stop an active AecDump recording */
 - (void)stopAecDump;
 
 @end
 
 NS_ASSUME_NONNULL_END