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 4d54a7125d2091b56cfe9c7ae261a0b1be3e4e62..97c0fd0e1ea021db1f39d319d333fffc0c9bf90b 100644
--- a/Source/core/dom/Document.h
+++ b/Source/core/dom/Document.h
@@ -315,8 +315,6 @@ 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);