Componentize renderer side of DNS prefetching.

components/dns_prefetch/common/prefetch_messages.h

Index: components/dns_prefetch/common/prefetch_messages.h
diff --git a/components/dns_prefetch/common/prefetch_messages.h b/components/dns_prefetch/common/prefetch_messages.h
new file mode 100644
index 0000000000000000000000000000000000000000..778bdeb961e5eb74579130198dc586c1895a5bbf
--- /dev/null
+++ b/components/dns_prefetch/common/prefetch_messages.h
@@ -0,0 +1,21 @@
+// 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 file, no traditional include guard.
+#include <string>
+#include <vector>
+
+#include "ipc/ipc_message_macros.h"
+#include "ipc/ipc_message_utils.h"
+
+#define IPC_MESSAGE_START DnsPrefetchMsgStart
+
+//-----------------------------------------------------------------------------
+// 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,
+                     std::vector<std::string> /* hostnames */)