Show a warning when using sync xhr.

Source/core/dom/Document.h

 /*
  * 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)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
@@ skipping 1023 matching lines @@
     virtual void trace(Visitor*) OVERRIDE;
 
     bool hasSVGFilterElementsRequiringLayerUpdate() const { return m_layerUpdateSVGFilterElements.size(); }
     void didRecalculateStyleForElement() { ++m_styleRecalcElementCounter; }
 
     AtomicString convertLocalName(const AtomicString&);
 
     virtual v8::Handle<v8::Object> wrap(v8::Handle<v8::Object> creationContext, v8::Isolate*) OVERRIDE;
     virtual v8::Handle<v8::Object> associateWithWrapper(const WrapperTypeInfo*, v8::Handle<v8::Object> wrapper, v8::Isolate*) OVERRIDE;
 
+    void setWarnedAboutSyncXHROnce() { m_warnAboutSyncXHROnce = true; }
+    bool didWarnAboutSyncXHROnce() { return m_warnAboutSyncXHROnce; }
+
 protected:
     Document(const DocumentInit&, DocumentClassFlags = DefaultDocumentClass);
 
     virtual void didUpdateSecurityOrigin() OVERRIDE FINAL;
 
     void clearXMLVersion() { m_xmlVersion = String(); }
 
 #if !ENABLE(OILPAN)
     virtual void dispose() OVERRIDE;
 #endif
@@ skipping 311 matching lines @@
 
     WillBeHeapHashSet<RawPtrWillBeMember<SVGUseElement> > m_useElementsNeedingUpdate;
     WillBeHeapHashSet<RawPtrWillBeMember<Element> > m_layerUpdateSVGFilterElements;
 
     bool m_hasViewportUnits;
 
     typedef WillBeHeapHashSet<RawPtrWillBeWeakMember<DocumentVisibilityObserver> > DocumentVisibilityObserverSet;
     DocumentVisibilityObserverSet m_visibilityObservers;
 
     int m_styleRecalcElementCounter;
+    bool m_warnAboutSyncXHROnce;

[kouhei (in TOK), 2014/10/01 11:38:44]

m_hasWarnedAboutSyncXHR?

I want to avoid adding the flag in Document as much as possible, but I don't
have a suggestion of alternative now...

 };
 
 inline bool Document::shouldOverrideLegacyDescription(ViewportDescription::Type origin)
 {
     // The different (legacy) meta tags have different priorities based on the type
     // regardless of which order they appear in the DOM. The priority is given by the
     // ViewportDescription::Type enum.
     return origin >= m_legacyViewportDescription.type;
 }
 
@@ skipping 25 matching lines @@
 Node* eventTargetNodeForDocument(Document*);
 
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showLiveDocumentInstances();
 #endif
 
 #endif // Document_h