Bug 1054908 - Ensure socket_child_ is released on main thread. r=mt

media/mtransport/nr_socket_prsock.cpp

@@ -1026,12 +1026,13 @@ void NrSocketIpc::create_m(const nsACString &host, const uint16_t port) {
   ReentrantMonitorAutoEnter mon(monitor_);
 
   nsresult rv;
-  socket_child_ = do_CreateInstance("@mozilla.org/udp-socket-child;1", &rv);
+  nsCOMPtr<nsIUDPSocketChild> socketChild = do_CreateInstance("@mozilla.org/udp-socket-child;1", &rv);
   if (NS_FAILED(rv)) {
     err_ = true;
     MOZ_ASSERT(false, "Failed to create UDPSocketChild");
   }
 
+  socket_child_ = new nsMainThreadPtrHolder<nsIUDPSocketChild>(socketChild);
   socket_child_->SetFilterName(nsCString("stun"));
 
   if (NS_FAILED(socket_child_->Bind(this, host, port))) {

media/mtransport/nr_socket_prsock.h

@@ -58,6 +58,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include "nsXPCOM.h"
 #include "nsIEventTarget.h"
 #include "nsIUDPSocketChild.h"
+#include "nsProxyRelease.h"
 
 #include "databuffer.h"
 #include "m_cpp_utils.h"
@@ -233,7 +234,7 @@ private:
   NrSocketIpcState state_;
   std::queue<RefPtr<nr_udp_message> > received_msgs_;
 
-  nsCOMPtr<nsIUDPSocketChild> socket_child_;
+  nsMainThreadPtrHandle<nsIUDPSocketChild> socket_child_;
   nsCOMPtr<nsIEventTarget> sts_thread_;
   const nsCOMPtr<nsIEventTarget> main_thread_;
   ReentrantMonitor monitor_;