Declarative resource hints go through mojo IPC to //content

third_party/WebKit/Source/core/page/ChromeClient.cpp

 /*
  * Copyright (C) 2006, 2007, 2009, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2012, Samsung Electronics. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 113 matching lines @@
     if (!canOpenModalIfDuringPageDismissal(frame->tree().top(), ChromeClient::PromptDialog, prompt))
         return false;
     return openJavaScriptDialog(frame, prompt, ChromeClient::PromptDialog, [this, frame, &prompt, &defaultValue, &result]() {
         return openJavaScriptPromptDelegate(frame, prompt, defaultValue, result);
     });
 }
 
 void ChromeClient::mouseDidMoveOverElement(const HitTestResult& result)
 {
     if (result.innerNode() && result.innerNode()->document().isDNSPrefetchEnabled())
-        prefetchDNS(result.absoluteLinkURL().host());
+        prefetchDNS(result.absoluteLinkURL());
 
     showMouseOverURL(result);
 
     setToolTip(result);
 }
 
 void ChromeClient::setToolTip(const HitTestResult& result)
 {
     // First priority is a tooltip for element with "title" attribute.
     TextDirection toolTipDirection;
@@ skipping 34 matching lines @@
 {
     // Defer loads in case the client method runs a new event loop that would
     // otherwise cause the load to continue while we're in the middle of
     // executing JavaScript.
     ScopedPageLoadDeferrer deferrer;
 
     printDelegate(frame);
 }
 
 } // namespace blink