Fix QUICHE standalone build by providing a missing platform impl

PiperOrigin-RevId: 516209653

quiche/common/platform/default/quiche_platform_impl/quiche_udp_socket_platform_impl.h

diff --git a/quiche/common/platform/default/quiche_platform_impl/quiche_udp_socket_platform_impl.h b/quiche/common/platform/default/quiche_platform_impl/quiche_udp_socket_platform_impl.h
index b42cfcc..e79ac22 100644
--- a/quiche/common/platform/default/quiche_platform_impl/quiche_udp_socket_platform_impl.h
+++ b/quiche/common/platform/default/quiche_platform_impl/quiche_udp_socket_platform_impl.h
@@ -23,6 +23,15 @@
 
 inline void SetGoogleSocketOptionsImpl(int /*fd*/) {}
 
+inline int GetEcnCmsgArgsPreserveDscpImpl(const int /*fd*/,
+                                          const int /*address_family*/,
+                                          uint8_t /*ecn_codepoint*/,
+                                          int& /*type*/, void* /*value*/,
+                                          socklen_t& /*value_len*/) {
+  // TODO(b/273081493): implement this.
+  return 0;
+}
+
 }  // namespace quiche
 
 #endif  // QUICHE_COMMON_PLATFORM_DEFAULT_QUICHE_PLATFORM_IMPL_QUICHE_UDP_SOCKET_PLATFORM_IMPL_H_