Adding Link header support for dns-prefetch

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 30 matching lines @@
 #include "core/frame/LocalDOMWindow.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/csp/ContentSecurityPolicy.h"
 #include "core/html/HTMLFrameOwnerElement.h"
 #include "core/html/parser/HTMLDocumentParser.h"
 #include "core/html/parser/TextResourceDecoder.h"
 #include "core/html/parser/ThreadedDataReceiver.h"
 #include "core/inspector/InspectorInstrumentation.h"
 #include "core/loader/FrameLoader.h"
 #include "core/loader/FrameLoaderClient.h"
+#include "core/loader/LinkLoader.h"
 #include "core/loader/UniqueIdentifier.h"
 #include "core/loader/appcache/ApplicationCacheHost.h"
 #include "core/page/FrameTree.h"
 #include "core/page/Page.h"
 #include "core/frame/Settings.h"
 #include "core/inspector/ConsoleMessage.h"
 #include "platform/Logging.h"
 #include "platform/UserGestureIndicator.h"
 #include "platform/mhtml/ArchiveResource.h"
 #include "platform/mhtml/ArchiveResourceCollection.h"
@@ skipping 341 matching lines @@
     if (frameLoader())
         cancelMainResourceLoad(ResourceError::cancelledError(m_request.url()));
     return;
 }
 
 void DocumentLoader::responseReceived(Resource* resource, const ResourceResponse& response, PassOwnPtr<WebDataConsumerHandle> handle)
 {
     ASSERT_UNUSED(resource, m_mainResource == resource);
     ASSERT_UNUSED(handle, !handle);
     RefPtr<DocumentLoader> protect(this);
+    ASSERT(frame());
 
     m_applicationCacheHost->didReceiveResponseForMainResource(response);
 
     // The memory cache doesn't understand the application cache or its caching rules. So if a main resource is served
     // from the application cache, ensure we don't save the result for future use. All responses loaded
     // from appcache will have a non-zero appCacheID().
     if (response.appCacheID())
         memoryCache()->remove(m_mainResource.get());
 
     DEFINE_STATIC_LOCAL(AtomicString, xFrameOptionHeader, ("x-frame-options", AtomicString::ConstructFromLiteral));
@@ skipping 12 matching lines @@
     }
 
     m_contentSecurityPolicy = ContentSecurityPolicy::create();
     m_contentSecurityPolicy->setOverrideURLForSelf(response.url());
     m_contentSecurityPolicy->didReceiveHeaders(ContentSecurityPolicyResponseHeaders(response));
     if (!m_contentSecurityPolicy->allowAncestors(m_frame, response.url())) {
         cancelLoadAfterXFrameOptionsOrCSPDenied(response);
         return;
     }
 
+    if (resource && resource->type() == Resource::MainResource)
+        LinkLoader::loadLinkFromHeader(response.httpHeaderField("Link"), frame()->document());
+
     ASSERT(!mainResourceLoader() || !mainResourceLoader()->defersLoading());
 
     m_response = response;
 
     if (isArchiveMIMEType(m_response.mimeType()) && m_mainResource->dataBufferingPolicy() != BufferData)
         m_mainResource->setDataBufferingPolicy(BufferData);
 
     if (!shouldContinueForResponse()) {
         InspectorInstrumentation::continueWithPolicyIgnore(m_frame, this, m_mainResource->identifier(), m_response);
         cancelMainResourceLoad(ResourceError::cancelledError(m_request.url()));
@@ skipping 356 matching lines @@
 // This is only called by FrameLoader::replaceDocumentWhileExecutingJavaScriptURL()
 void DocumentLoader::replaceDocumentWhileExecutingJavaScriptURL(const DocumentInit& init, const String& source, Document* ownerDocument)
 {
     m_writer = createWriterFor(ownerDocument, init, mimeType(), m_writer ? m_writer->encoding() : emptyAtom, true, ForceSynchronousParsing);
     if (!source.isNull())
         m_writer->appendReplacingData(source);
     endWriting(m_writer.get());
 }
 
 } // namespace blink