Update from https://crrev.com/315085

net/udp/udp_client_socket.h

Index: net/udp/udp_client_socket.h
diff --git a/net/udp/udp_client_socket.h b/net/udp/udp_client_socket.h
index 427db7e2c502b818141a0fab3d2c9b789a29f172..7b4e1a6957e504e9180e8d75a1e379caeb9d6e04 100644
--- a/net/udp/udp_client_socket.h
+++ b/net/udp/udp_client_socket.h
@@ -38,6 +38,12 @@ class NET_EXPORT_PRIVATE UDPClientSocket : public DatagramClientSocket {
   int SetSendBufferSize(int32 size) override;
   const BoundNetLog& NetLog() const override;
 
+#if defined(OS_WIN)
+  // Switch to use non-blocking IO. Must be called right after construction and
+  // before other calls.
+  void UseNonBlockingIO();
+#endif
+
  private:
   UDPSocket socket_;
   DISALLOW_COPY_AND_ASSIGN(UDPClientSocket);