Implement JSValue for more structures

Previously was only implemented for PeerConnection.

datachannel_js.go

@@ -36,6 +36,11 @@ type DataChannel struct {
 	api *API
 }
 
+// JSValue returns the underlying RTCDataChannel
+func (d *DataChannel) JSValue() js.Value {
+	return d.underlying
+}
+
 // OnOpen sets an event handler which is invoked when
 // the underlying data transport has been established (or re-established).
 func (d *DataChannel) OnOpen(f func()) {

dtlstransport_js.go

@@ -17,6 +17,11 @@ type DTLSTransport struct {
 	underlying js.Value
 }
 
+// JSValue returns the underlying RTCDtlsTransport
+func (r *DTLSTransport) JSValue() js.Value {
+	return r.underlying
+}
+
 // ICETransport returns the currently-configured *ICETransport or nil
 // if one has not been configured
 func (r *DTLSTransport) ICETransport() *ICETransport {

icetransport_js.go

@@ -15,6 +15,11 @@ type ICETransport struct {
 	underlying js.Value
 }
 
+// JSValue returns the underlying RTCIceTransport
+func (t *ICETransport) JSValue() js.Value {
+	return t.underlying
+}
+
 // GetSelectedCandidatePair returns the selected candidate pair on which packets are sent
 // if there is no selected pair nil is returned
 func (t *ICETransport) GetSelectedCandidatePair() (*ICECandidatePair, error) {

rtpreceiver_js.go

@@ -13,3 +13,8 @@ type RTPReceiver struct {
 	// Pointer to the underlying JavaScript RTCRTPReceiver object.
 	underlying js.Value
 }
+
+// JSValue returns the underlying RTCRtpReceiver
+func (r *RTPReceiver) JSValue() js.Value {
+	return r.underlying
+}

rtpsender_js.go

@@ -13,3 +13,8 @@ type RTPSender struct {
 	// Pointer to the underlying JavaScript RTCRTPSender object.
 	underlying js.Value
 }
+
+// JSValue returns the underlying RTCRtpSender
+func (s *RTPSender) JSValue() js.Value {
+	return s.underlying
+}

rtptransceiver_js.go

@@ -16,6 +16,11 @@ type RTPTransceiver struct {
 	underlying js.Value
 }
 
+// JSValue returns the underlying RTCRtpTransceiver
+func (r *RTPTransceiver) JSValue() js.Value {
+	return r.underlying
+}
+
 // Direction returns the RTPTransceiver's current direction
 func (r *RTPTransceiver) Direction() RTPTransceiverDirection {
 	return NewRTPTransceiverDirection(r.underlying.Get("direction").String())

sctptransport_js.go

@@ -14,6 +14,11 @@ type SCTPTransport struct {
 	underlying js.Value
 }
 
+// JSValue returns the underlying RTCSctpTransport
+func (r *SCTPTransport) JSValue() js.Value {
+	return r.underlying
+}
+
 // Transport returns the DTLSTransport instance the SCTPTransport is sending over.
 func (r *SCTPTransport) Transport() *DTLSTransport {
 	underlying := r.underlying.Get("transport")