Remove LinkHeader runtime flag (status=stable)

third_party/WebKit/Source/core/loader/LinkLoader.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 304 matching lines @@
             continue;
         if (mediaPolicy == OnlyLoadNonMedia && !header.media().isEmpty())
             continue;
 
         LinkRelAttribute relAttribute(header.rel());
         KURL url(baseURL, header.url());
         // Sanity check to avoid re-entrancy here.
         if (url == baseURL)
             continue;
         if (canLoadResources != OnlyLoadResources) {
-            if (RuntimeEnabledFeatures::linkHeaderEnabled())
-                dnsPrefetchIfNeeded(relAttribute, url, *document, networkHintsInterface, LinkCalledFromHeader);
+            dnsPrefetchIfNeeded(relAttribute, url, *document, networkHintsInterface, LinkCalledFromHeader);
 
             if (RuntimeEnabledFeatures::linkPreconnectEnabled())
                 preconnectIfNeeded(relAttribute, url, *document, crossOriginAttributeValue(header.crossOrigin()), networkHintsInterface, LinkCalledFromHeader);
         }
         if (canLoadResources != DoNotLoadResources) {
             bool errorOccurred = false;
             if (RuntimeEnabledFeatures::linkPreloadEnabled()) {
                 ViewportDescription* viewportDescription = (viewportDescriptionWrapper && viewportDescriptionWrapper->set) ? &(viewportDescriptionWrapper->description) : nullptr;
                 preloadIfNeeded(relAttribute, url, *document, header.as(), header.mimeType(), header.media(), crossOriginAttributeValue(header.crossOrigin()), LinkCalledFromHeader, errorOccurred, viewportDescription);
             }
@@ skipping 64 matching lines @@
 DEFINE_TRACE(LinkLoader)
 {
     visitor->trace(m_client);
     visitor->trace(m_prerender);
     visitor->trace(m_linkPreloadResourceClient);
     ResourceOwner<Resource, ResourceClient>::trace(visitor);
     PrerenderClient::trace(visitor);
 }
 
 } // namespace blink