Revert of Add a parser for Link headers

Source/core/loader/LinkHeader.h

-// Copyright 2015 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 LinkHeader_h
-#define LinkHeader_h
-
-#include "wtf/text/WTFString.h"
-
-namespace blink {
-
-class LinkHeader {
-public:
-    LinkHeader(const String& header);
-
-    const String url() const { return m_url; };
-    const String rel() const { return m_rel; };
-    bool valid() const { return m_isValid; };
-
-    enum LinkParameterName {
-        LinkParameterUnknown,
-        LinkParameterRel,
-    };
-
-private:
-    template <typename CharType>
-    bool init(CharType* headerValue, unsigned len);
-    void setValue(LinkParameterName, String value);
-
-    String m_url;
-    String m_rel;
-    bool m_isValid;
-};
-
-}
-
-#endif