Add support for rel=next to Prerender in Blink.

Source/platform/Prerender.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 32 matching lines @@
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 class WebPrerender;
 }
 
 namespace WebCore {
 
 class PrerenderClient;
 
+// PrerenderRelType is a bitfield since multiple rel attributes can be set
+// on the same link.
+enum PrerenderRelType {
+    PrerenderRelTypePrerender = 0x1,
+    PrerenderRelTypeNext = 0x2,
+};
+
 class PLATFORM_EXPORT Prerender : public RefCounted<Prerender> {
     WTF_MAKE_NONCOPYABLE(Prerender);
 public:
     class ExtraData : public RefCounted<ExtraData> {
     public:
         virtual ~ExtraData() { }
     };
 
-    static PassRefPtr<Prerender> create(PrerenderClient*, const KURL&, const String& referrer, ReferrerPolicy);
+    static PassRefPtr<Prerender> create(PrerenderClient*, const KURL&, unsigned relTypes, const String& referrer, ReferrerPolicy);
     ~Prerender();
 
     void removeClient();
 
     void add();
     void cancel();
     void abandon();
 
     const KURL& url() const { return m_url; }
+    unsigned relTypes() const { return m_relTypes; }
     const String& referrer() const { return m_referrer; }
     ReferrerPolicy referrerPolicy() const { return m_referrerPolicy; }
 
     void setExtraData(PassRefPtr<ExtraData> extraData) { m_extraData = extraData; }
     ExtraData* extraData() { return m_extraData.get(); }
 
     void didStartPrerender();
     void didStopPrerender();
     void didSendLoadForPrerender();
     void didSendDOMContentLoadedForPrerender();
 
 private:
-    Prerender(PrerenderClient*, const KURL&, const String& referrer, ReferrerPolicy);
+    Prerender(PrerenderClient*, const KURL&, unsigned relTypes, const String& referrer, ReferrerPolicy);
 
     PrerenderClient* m_client;
 
     const KURL m_url;
+    const unsigned m_relTypes;
     const String m_referrer;
     const ReferrerPolicy m_referrerPolicy;
 
     RefPtr<ExtraData> m_extraData;
 };
 
 }
 
 #endif // Prerender_h