Enable new multicol for testing and experimental web platform features.

Source/core/dom/Document.h

Index: Source/core/dom/Document.h
diff --git a/Source/core/dom/Document.h b/Source/core/dom/Document.h
index e75547ab04e8583d40bdc8dd70ef6b0236e1e27d..b81e61710bcc91bb7a50d4596151cf6d558cfc58 100644
--- a/Source/core/dom/Document.h
+++ b/Source/core/dom/Document.h
@@ -314,8 +314,6 @@ public:
     PassRefPtrWillBeRawPtr<Element> createElementNS(const AtomicString& namespaceURI, const AtomicString& qualifiedName, ExceptionState&);
     PassRefPtrWillBeRawPtr<Element> createElement(const QualifiedName&, bool createdByParser);
 
-    bool regionBasedColumnsEnabled() const;
-
     Element* elementFromPoint(int x, int y) const;
     Vector<Element*> elementsFromPoint(int x, int y) const;
     PassRefPtrWillBeRawPtr<Range> caretRangeFromPoint(int x, int y);