Bug 1859474 - Don't release TCPSocket on socket thread. r=#necko-reviewers a=pascalc

Since TCPSocket might be released on the socket thread, it might cause a
crash when TCPSocket is destroyed on this thread.

Since we use mozilla::SyncRunnable::DispatchToThread, this is synchronous
call. So it is unnecessary to touch reference count on this thread.

Differential Revision: https://phabricator.services.mozilla.com/D251990

dom/network/TCPSocket.cpp

@@ -470,8 +470,10 @@ void TCPSocket::ActivateTLS() {
     return;
   }
 
-  auto CallActivateTLS = [sock = RefPtr{this}]() mutable {
-    sock->ActivateTLSHelper();
+  // Since we use mozilla::SyncRunnable::DispatchToThread, it is unnecessary to
+  // AddRef/Release TCPSocket in CallActivateTLS.
+  auto CallActivateTLS = [&self = *this]() mutable {
+    self.ActivateTLSHelper();
   };
   mozilla::SyncRunnable::DispatchToThread(
       socketThread,