Allow filename suggestions via a[download] for data URIs

Source/core/html/HTMLAnchorElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  * Copyright (C) 2003, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * 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
@@ skipping 366 matching lines @@
     ResourceRequest request(completedURL);
     if (prefetchEventHandler()->hasIssuedPreconnect())
         frame->loader().client()->dispatchWillRequestAfterPreconnect(request);
     if (hasAttribute(downloadAttr)) {
         if (!hasRel(RelationNoReferrer)) {
             String referrer = SecurityPolicy::generateReferrerHeader(document().referrerPolicy(), completedURL, document().outgoingReferrer());
             if (!referrer.isEmpty())
                 request.setHTTPReferrer(Referrer(referrer, document().referrerPolicy()));
         }
 
-        bool isSameOrigin = document().securityOrigin()->canRequest(completedURL);
+        bool isSameOrigin = completedURL.protocolIsData() || document().securityOrigin()->canRequest(completedURL);
         const AtomicString& suggestedName = (isSameOrigin ? fastGetAttribute(downloadAttr) : nullAtom);
 
         frame->loader().client()->loadURLExternally(request, NavigationPolicyDownload, suggestedName);
     } else {
         FrameLoadRequest frameRequest(&document(), request, target());
         frameRequest.setTriggeringEvent(event);
         if (hasRel(RelationNoReferrer))
             frameRequest.setShouldSendReferrer(NeverSendReferrer);
         frame->loader().load(frameRequest);
     }
@@ skipping 186 matching lines @@
     return isLink();
 }
 
 void HTMLAnchorElement::trace(Visitor* visitor)
 {
     visitor->trace(m_prefetchEventHandler);
     HTMLElement::trace(visitor);
 }
 
 }