Added chrome-side support for link rel=preconnect

chrome/common/render_messages.h

 // Copyright (c) 2012 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 <stdint.h>
 #include <map>
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 527 matching lines @@
 IPC_SYNC_MESSAGE_ROUTED2_1(ChromeViewHostMsg_GetSearchProviderInstallState,
                            GURL /* page url */,
                            GURL /* inquiry url */,
                            search_provider::InstallState /* install */)
 
 // Sends back stats about the V8 heap.
 IPC_MESSAGE_CONTROL2(ChromeViewHostMsg_V8HeapStats,
                      int /* size of heap (allocated from the OS) */,
                      int /* bytes in use */)
 
-// Request for preconnect to host providing resource specified by URL
-IPC_MESSAGE_CONTROL1(ChromeViewHostMsg_Preconnect,
-                     GURL /* preconnect target url */)
-
 // Notifies when a plugin couldn't be loaded because it's outdated.
 IPC_MESSAGE_ROUTED2(ChromeViewHostMsg_BlockedOutdatedPlugin,
                     int /* placeholder ID */,
                     std::string /* plug-in group identifier */)
 
 // Notifies when a plugin couldn't be loaded because it requires
 // user authorization.
 IPC_MESSAGE_ROUTED2(ChromeViewHostMsg_BlockedUnauthorizedPlugin,
                     base::string16 /* name */,
                     std::string /* plug-in group identifier */)
@@ skipping 104 matching lines @@
 
 #if defined(ENABLE_PLUGINS)
 // Sent by the renderer to check if crash reporting is enabled.
 IPC_SYNC_MESSAGE_CONTROL0_1(ChromeViewHostMsg_IsCrashReportingEnabled,
                             bool /* enabled */)
 #endif
 
 // Sent by the renderer to indicate that a fields trial has been activated.
 IPC_MESSAGE_CONTROL1(ChromeViewHostMsg_FieldTrialActivated,
                      std::string /* name */)