(Re-)introduce AncestorThrottle to handle 'X-Frame-Options'.

third_party/WebKit/Source/core/dom/DocumentInit.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
@@ skipping 78 matching lines @@
   if (m_importsController)
     return m_importsController->master()->frame();
   return 0;
 }
 
 SandboxFlags DocumentInit::getSandboxFlags() const {
   DCHECK(frameForSecurityContext());
   FrameLoader* loader = &frameForSecurityContext()->loader();
   SandboxFlags flags = loader->effectiveSandboxFlags();
 
-  // If the load was blocked by X-Frame-Options or CSP, force the Document's
-  // origin to be unique, so that the blocked document appears to be a normal
-  // cross-origin document's load per CSP spec:
-  // https://www.w3.org/TR/CSP2/#directive-frame-ancestors
+  // If the load was blocked by CSP, force the Document's origin to be unique,
+  // so that the blocked document appears to be a normal cross-origin document's
+  // load per CSP spec: https://www.w3.org/TR/CSP3/#directive-frame-ancestors.
   if (loader->documentLoader() &&
-      loader->documentLoader()->wasBlockedAfterXFrameOptionsOrCSP())
+      loader->documentLoader()->wasBlockedAfterCSP()) {
     flags |= SandboxOrigin;
+  }
 
   return flags;
 }
 
 WebInsecureRequestPolicy DocumentInit::getInsecureRequestPolicy() const {
   DCHECK(frameForSecurityContext());
   return frameForSecurityContext()->loader().getInsecureRequestPolicy();
 }
 
 SecurityContext::InsecureNavigationsSet*
@@ skipping 54 matching lines @@
 Document* DocumentInit::contextDocument() const {
   return m_contextDocument;
 }
 
 DocumentInit DocumentInit::fromContext(Document* contextDocument,
                                        const KURL& url) {
   return DocumentInit(url, 0, contextDocument, 0);
 }
 
 }  // namespace blink