Move UseNonBlockingIO from a windows-only method

content/browser/renderer_host/p2p/socket_host_udp_unittest.cc

Index: content/browser/renderer_host/p2p/socket_host_udp_unittest.cc
diff --git a/content/browser/renderer_host/p2p/socket_host_udp_unittest.cc b/content/browser/renderer_host/p2p/socket_host_udp_unittest.cc
index f01e1e40c7c4aef6d2192c20c855340c217fecc5..83b818eab0f12e92a271bb6c718cf2874b497af0 100644
--- a/content/browser/renderer_host/p2p/socket_host_udp_unittest.cc
+++ b/content/browser/renderer_host/p2p/socket_host_udp_unittest.cc
@@ -64,6 +64,8 @@ class FakeDatagramServerSocket : public net::DatagramServerSocket {
     return 0;
   }
 
+  void UseNonBlockingIO() override {}
+
   int Listen(const net::IPEndPoint& address) override {
     if (used_ports_) {
       for (auto used_port : *used_ports_) {