ObjC: RTCVideoSource cleanup

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

Index: webrtc/sdk/objc/Framework/Headers/WebRTC/RTCVideoCapturer.h
diff --git a/webrtc/sdk/objc/Framework/Headers/WebRTC/RTCVideoCapturer.h b/webrtc/sdk/objc/Framework/Headers/WebRTC/RTCVideoCapturer.h
index 47d5a47acfdd440b4790b63f94ce1dc70230c340..3addec83b1dab62430bbab7448aa8d1cc6f87f0f 100644
--- a/webrtc/sdk/objc/Framework/Headers/WebRTC/RTCVideoCapturer.h
+++ b/webrtc/sdk/objc/Framework/Headers/WebRTC/RTCVideoCapturer.h
@@ -15,14 +15,17 @@ NS_ASSUME_NONNULL_BEGIN
 @class RTCVideoCapturer;
 
 RTC_EXPORT
-
-@protocol RTCVideoCapturerDelegate
+@protocol RTCVideoCapturerDelegate <NSObject>
 - (void)capturer:(RTCVideoCapturer *)capturer didCaptureVideoFrame:(RTCVideoFrame *)frame;
 @end
 
+RTC_EXPORT
 @interface RTCVideoCapturer : NSObject
-- (instancetype)initWithDelegate:(id<RTCVideoCapturerDelegate>)delegate;
+
 @property(nonatomic, readonly, weak) id<RTCVideoCapturerDelegate> delegate;
+
+- (instancetype)initWithDelegate:(id<RTCVideoCapturerDelegate>)delegate;
+
 @end
 
 NS_ASSUME_NONNULL_END