Implement support for link type serviceworker in link elements.

third_party/WebKit/Source/core/html/LinkRelAttribute.cpp

 /*
  * Copyright (C) 2011 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 29 matching lines @@
     , m_isStyleSheet(false)
     , m_isAlternate(false)
     , m_isDNSPrefetch(false)
     , m_isPreconnect(false)
     , m_isLinkPrefetch(false)
     , m_isLinkPreload(false)
     , m_isLinkPrerender(false)
     , m_isLinkNext(false)
     , m_isImport(false)
     , m_isManifest(false)
+    , m_isServiceWorker(false)
 {
     if (rel.isEmpty())
         return;
     String relCopy = rel;
     relCopy.replace('\n', ' ');
     Vector<String> list;
     relCopy.split(' ', list);
     for (const String& linkType : list) {
         if (equalIgnoringCase(linkType, "stylesheet")) {
             if (!m_isImport)
@@ skipping 21 matching lines @@
         } else if (equalIgnoringCase(linkType, "prerender")) {
             m_isLinkPrerender = true;
         } else if (equalIgnoringCase(linkType, "next")) {
             m_isLinkNext = true;
         } else if (equalIgnoringCase(linkType, "apple-touch-icon")) {
             m_iconType = TouchIcon;
         } else if (equalIgnoringCase(linkType, "apple-touch-icon-precomposed")) {
             m_iconType = TouchPrecomposedIcon;
         } else if (equalIgnoringCase(linkType, "manifest")) {
             m_isManifest = true;
+        } else if (equalIgnoringCase(linkType, "serviceworker")) {
+            m_isServiceWorker = true;
         }
         // Adding or removing a value here requires you to update RelList::supportedTokens()
     }
 }
 
 } // namespace blink