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

third_party/WebKit/Source/platform/network/HTTPParsers.cpp

 /*
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. http://www.torchmobile.com/
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2011 Apple 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 502 matching lines @@
     }
 }
 
 ContentTypeOptionsDisposition parseContentTypeOptionsHeader(const String& header)
 {
     if (header.stripWhiteSpace().lower() == "nosniff")
         return ContentTypeOptionsNosniff;
     return ContentTypeOptionsNone;
 }
 
-XFrameOptionsDisposition parseXFrameOptionsHeader(const String& header)
-{
-    XFrameOptionsDisposition result = XFrameOptionsInvalid;
-
-    if (header.isEmpty())
-        return result;
-
-    Vector<String> headers;
-    header.split(',', headers);
-
-    bool hasValue = false;
-    for (size_t i = 0; i < headers.size(); i++) {
-        String currentHeader = headers[i].stripWhiteSpace();
-        XFrameOptionsDisposition currentValue = XFrameOptionsInvalid;
-        if (equalIgnoringCase(currentHeader, "deny"))
-            currentValue = XFrameOptionsDeny;
-        else if (equalIgnoringCase(currentHeader, "sameorigin"))
-            currentValue = XFrameOptionsSameOrigin;
-        else if (equalIgnoringCase(currentHeader, "allowall"))
-            currentValue = XFrameOptionsAllowAll;
-
-        if (!hasValue)
-            result = currentValue;
-        else if (result != currentValue)
-            return XFrameOptionsConflict;
-        hasValue = true;
-    }
-    return result;
-}
-
 static bool isCacheHeaderSeparator(UChar c)
 {
     // See RFC 2616, Section 2.2
     switch (c) {
     case '(':
     case ')':
     case '<':
     case '>':
     case '@':
     case ',':
@@ skipping 188 matching lines @@
         if (option == Suborigin::SuboriginPolicyOptions::None)
             messages.append("Ignoring unknown suborigin policy option " + optionName + ".");
         else
             suborigin->addPolicyOption(option);
     }
 
     return true;
 }
 
 } // namespace blink