Enable resource prefetch from the browser process.

chrome/common/prefetch_messages.h

Index: chrome/common/prefetch_messages.h
diff --git a/chrome/common/prefetch_messages.h b/chrome/common/prefetch_messages.h
new file mode 100644
index 0000000000000000000000000000000000000000..e4f691ac1f4e156741870b6f19b23a2d1c6e8ecc
--- /dev/null
+++ b/chrome/common/prefetch_messages.h
@@ -0,0 +1,19 @@
+// Copyright (c) 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 message file, no traditional include guard.
+#include "ipc/ipc_message.h"
+#include "ipc/ipc_message_macros.h"
+#include "ipc/ipc_param_traits.h"
+#include "url/gurl.h"
+
+#define IPC_MESSAGE_START PrefetchMsgStart
+
+// Prefetch Messages
+// These are messages sent from the browser to the renderer related to
+// prefetching.
+
+// Instructs the renderer to launch a prefetch within its context.
+IPC_MESSAGE_ROUTED1(PrefetchMsg_Prefetch,
+                    GURL /* url */)