Add support for rel=next to Prerender in Blink.

Source/core/html/LinkRelAttribute.h

Index: Source/core/html/LinkRelAttribute.h
diff --git a/Source/core/html/LinkRelAttribute.h b/Source/core/html/LinkRelAttribute.h
index a124012055d8b1ad84744c34746f6fafeb6f2735..9c2a147225e1f8e8bb0d2450f2b726c65b820683 100644
--- a/Source/core/html/LinkRelAttribute.h
+++ b/Source/core/html/LinkRelAttribute.h
@@ -52,6 +52,7 @@ public:
     bool isLinkPrefetch() const { return m_isLinkPrefetch; }
     bool isLinkSubresource() const { return m_isLinkSubresource; }
     bool isLinkPrerender() const { return m_isLinkPrerender; }
+    bool isLinkNext() const { return m_isLinkNext; }
     bool isImport() const { return m_isImport; }
 
 private:
@@ -62,6 +63,7 @@ private:
     bool m_isLinkPrefetch : 1;
     bool m_isLinkSubresource : 1;
     bool m_isLinkPrerender : 1;
+    bool m_isLinkNext : 1;
     bool m_isImport : 1;
 };