POSIX only: Move client socket functionality from TCPClientSocket into TCPSocket.

net/socket/tcp_socket.h

Index: net/socket/tcp_socket.h
diff --git a/net/socket/tcp_socket.h b/net/socket/tcp_socket.h
index aea8f12d65e0ae67891cefd702ab941600e9b643..8b36fade758e05db222d9fa4e2ee739e110b2779 100644
--- a/net/socket/tcp_socket.h
+++ b/net/socket/tcp_socket.h
@@ -6,6 +6,7 @@
 #define NET_SOCKET_TCP_SOCKET_H_
 
 #include "build/build_config.h"
+#include "net/base/net_export.h"
 
 #if defined(OS_WIN)
 #include "net/socket/tcp_socket_win.h"
@@ -15,6 +16,13 @@
 
 namespace net {
 
+// Enable/disable experimental TCP FastOpen option.
+// Not thread safe.  Must be called during initialization/startup only.
+NET_EXPORT void SetTCPFastOpenEnabled(bool value);
+
+// Check if the TCP FastOpen option is enabled.
+bool IsTCPFastOpenEnabled();
+
 // TCPSocket provides a platform-independent interface for TCP sockets.
 //
 // It is recommended to use TCPClientSocket/TCPServerSocket instead of this