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..6146d01b6e9dfccfd255cbf0f20f8bdea1e39678
--- /dev/null
+++ b/chrome/common/prefetch_messages.h
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+// 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 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 */)