Revert of net: merge two versions of SetTCPNoDelay() function into one

net/socket/tcp_socket_win.cc

Index: net/socket/tcp_socket_win.cc
diff --git a/net/socket/tcp_socket_win.cc b/net/socket/tcp_socket_win.cc
index 827dd72f340edacfca54e9fed6c89d1f9ff0177e..872a56026293cd4c5ee60fba0bcbdb2762c8ec9e 100644
--- a/net/socket/tcp_socket_win.cc
+++ b/net/socket/tcp_socket_win.cc
@@ -49,6 +49,36 @@
 }
 
 // Disable Nagle.
+// The Nagle implementation on windows is governed by RFC 896.  The idea
+// behind Nagle is to reduce small packets on the network.  When Nagle is
+// enabled, if a partial packet has been sent, the TCP stack will disallow
+// further *partial* packets until an ACK has been received from the other
+// side.  Good applications should always strive to send as much data as
+// possible and avoid partial-packet sends.  However, in most real world
+// applications, there are edge cases where this does not happen, and two
+// partial packets may be sent back to back.  For a browser, it is NEVER
+// a benefit to delay for an RTT before the second packet is sent.
+//
+// As a practical example in Chromium today, consider the case of a small
+// POST.  I have verified this:
+//     Client writes 649 bytes of header  (partial packet #1)
+//     Client writes 50 bytes of POST data (partial packet #2)
+// In the above example, with Nagle, a RTT delay is inserted between these
+// two sends due to nagle.  RTTs can easily be 100ms or more.  The best
+// fix is to make sure that for POSTing data, we write as much data as
+// possible and minimize partial packets.  We will fix that.  But disabling
+// Nagle also ensure we don't run into this delay in other edge cases.
+// See also:
+//    http://technet.microsoft.com/en-us/library/bb726981.aspx
+bool DisableNagle(SOCKET socket, bool disable) {
+  BOOL val = disable ? TRUE : FALSE;
+  int rv = setsockopt(socket, IPPROTO_TCP, TCP_NODELAY,
+                      reinterpret_cast<const char*>(&val),
+                      sizeof(val));
+  DCHECK(!rv) << "Could not disable nagle";
+  return rv == 0;
+}
+
 // Enable TCP Keep-Alive to prevent NAT routers from timing out TCP
 // connections. See http://crbug.com/27400 for details.
 bool SetTCPKeepAlive(SOCKET socket, BOOL enable, int delay_secs) {
@@ -549,7 +579,7 @@
 }
 
 void TCPSocketWin::SetDefaultOptionsForClient() {
-  SetTCPNoDelay(socket_, /*no_delay=*/true);
+  DisableNagle(socket_, true);
   SetTCPKeepAlive(socket_, true, kTCPKeepAliveSeconds);
 }
 
@@ -594,7 +624,7 @@
 }
 
 bool TCPSocketWin::SetNoDelay(bool no_delay) {
-  return SetTCPNoDelay(socket_, no_delay);
+  return DisableNagle(socket_, no_delay);
 }
 
 void TCPSocketWin::Close() {