add RTC_EXPORT on  RTCRtpTransceiverInit

Bug: webrtc:9592
Change-Id: Icdaf69cf6ab00f299c3b31a43ce30a6b00b9646d
Reviewed-on: https://webrtc-review.googlesource.com/92580
Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
Commit-Queue: Kári Helgason <kthelgason@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24216}
diff --git a/sdk/objc/Framework/Headers/WebRTC/RTCRtpTransceiver.h b/sdk/objc/Framework/Headers/WebRTC/RTCRtpTransceiver.h
index db0fd1c..27fccc4 100644
--- a/sdk/objc/Framework/Headers/WebRTC/RTCRtpTransceiver.h
+++ b/sdk/objc/Framework/Headers/WebRTC/RTCRtpTransceiver.h
@@ -28,6 +28,7 @@
  *  RTCPeerConnection.addTransceiver.
  *  https://w3c.github.io/webrtc-pc/#dom-rtcrtptransceiverinit
  */
+RTC_EXPORT
 @interface RTCRtpTransceiverInit : NSObject
 
 /** Direction of the RTCRtpTransceiver. See RTCRtpTransceiver.direction. */