Add <link rel=next> support to prerender.

chrome/common/prerender_types.h

+// 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.
+
+#ifndef CHROME_COMMON_PRERENDER_TYPES_H_
+#define CHROME_COMMON_PRERENDER_TYPES_H_
+
+namespace prerender {
+
+// PrerenderRelType is a bitfield since multiple rel attributes can be set
+// on the same link. Must be the same as blink::WebPrerenderRelType.
+enum PrerenderRelType {
+  PrerenderRelTypePrerender = 0x1,
+  PrerenderRelTypeNext = 0x2,
+};
+
+}  // namespace prerender
+
+#endif  // CHROME_COMMON_PRERENDER_TYPES_H_