Implement the logic to find the correct <link> for Manifest in Document.

Source/core/loader/DocumentLoader.cpp

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
  * 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 257 matching lines @@
 
     if (!m_mainDocumentError.isNull())
         return;
     clearMainResourceLoader();
     if (!frameLoader()->stateMachine()->creatingInitialEmptyDocument())
         frameLoader()->checkLoadComplete();
 
     // If the document specified an application cache manifest, it violates the author's intent if we store it in the memory cache
     // and deny the appcache the chance to intercept it in the future, so remove from the memory cache.
     if (m_frame) {
-        if (m_mainResource && m_frame->document()->hasManifest())
+        if (m_mainResource && m_frame->document()->hasAppCacheManifest())
             memoryCache()->remove(m_mainResource.get());
     }
     m_applicationCacheHost->finishedLoadingMainResource();
     clearMainResourceHandle();
 }
 
 bool DocumentLoader::isRedirectAfterPost(const ResourceRequest& newRequest, const ResourceResponse& redirectResponse)
 {
     int status = redirectResponse.httpStatusCode();
     if (((status >= 301 && status <= 303) || status == 307)
@@ skipping 533 matching lines @@
 void DocumentLoader::replaceDocument(const String& source, Document* ownerDocument)
 {
     m_frame->loader().stopAllLoaders();
     m_writer = createWriterFor(m_frame, ownerDocument, m_frame->document()->url(), mimeType(), m_writer ? m_writer->encoding() : emptyAtom,  m_writer ? m_writer->encodingWasChosenByUser() : false, true);
     if (!source.isNull())
         m_writer->appendReplacingData(source);
     endWriting(m_writer.get());
 }
 
 } // namespace WebCore