Added chrome-side support for link rel=preconnect

components/network_hints/common/network_hints_messages.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Multiply-included file, no traditional include guard.
 #include <string>
 #include <vector>
 
 #include "components/network_hints/common/network_hints_common.h"
+#include "content/public/common/common_param_traits.h"
 #include "ipc/ipc_message_macros.h"
 #include "ipc/ipc_message_utils.h"
 
 // Singly-included section for custom IPC traits.
 #ifndef COMPONENTS_NETWORK_HINTS_COMMON_NETWORK_HINTS_MESSAGES_H_
 #define COMPONENTS_NETWORK_HINTS_COMMON_NETWORK_HINTS_MESSAGES_H_
 
 namespace IPC {
 
 template <>
 struct ParamTraits<network_hints::LookupRequest> {
   typedef network_hints::LookupRequest param_type;
   static void Write(Message* m, const param_type& p);
   static bool Read(const Message* m, PickleIterator* iter, param_type* r);
   static void Log(const param_type& p, std::string* l);
 };
 
 }  // namespace IPC
 
 #endif  // COMPONENTS_NETWORK_HINTS_COMMON_NETWORK_HINTS_MESSAGES_H_
 
-#define IPC_MESSAGE_START DnsPrefetchMsgStart
+#define IPC_MESSAGE_START NetworkHintsMsgStart
 
 //-----------------------------------------------------------------------------
 // Host messages
 // These are messages sent from the renderer process to the browser process.
 
 // Request for a DNS prefetch of the names in the array.
 // NameList is typedef'ed std::vector<std::string>
-IPC_MESSAGE_CONTROL1(DnsPrefetchMsg_RequestPrefetch,
+IPC_MESSAGE_CONTROL1(NetworkHintsMsg_DNSPrefetch,
                      network_hints::LookupRequest)
+
+
+// Request for preconnect to host providing resource specified by URL
+IPC_MESSAGE_CONTROL2(NetworkHintsMsg_Preconnect,
+                     GURL /* preconnect target url */,
+                     int  /* number of connections */)
+