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

third_party/WebKit/Source/core/loader/FrameLoader.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) Research In Motion Limited 2009. 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:
@@ skipping 172 matching lines @@
   // events, abort XHR requests and detach the document. Returns true if the
   // frame is ready to receive the next commit, or false otherwise.
   bool prepareForCommit();
 
   void commitProvisionalLoad();
 
   FrameLoaderStateMachine* stateMachine() const { return &m_stateMachine; }
 
   void applyUserAgent(ResourceRequest&);
 
-  bool shouldInterruptLoadForXFrameOptions(const String&,
-                                           const KURL&,
-                                           unsigned long requestIdentifier);
-
   bool allAncestorsAreComplete() const;  // including this
 
   bool shouldClose(bool isReload = false);
   void dispatchUnloadEvent();
 
   bool allowPlugins(ReasonForCallingAllowPlugins);
 
   void updateForSameDocumentNavigation(const KURL&,
                                        SameDocumentNavigationSource,
                                        PassRefPtr<SerializedScriptValue>,
@@ skipping 119 matching lines @@
   SandboxFlags m_forcedSandboxFlags;
 
   bool m_dispatchingDidClearWindowObjectInMainWorld;
   bool m_protectProvisionalLoader;
   bool m_isNavigationHandledByClient;
 };
 
 }  // namespace blink
 
 #endif  // FrameLoader_h