Remove CSS regions support, keeping a bare minimum to support "region-based" multicol.

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index 87d874a1b19f9ca108cde106e3fe8344f7202af0..cd5151cdc64d86f4691f5a7f7cfa32bd860b026c 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -62,7 +62,6 @@
 #include "core/dom/Comment.h"
 #include "core/dom/ContextFeatures.h"
 #include "core/dom/DOMImplementation.h"
-#include "core/dom/DOMNamedFlowCollection.h"
 #include "core/dom/DocumentFragment.h"
 #include "core/dom/DocumentLifecycleNotifier.h"
 #include "core/dom/DocumentLifecycleObserver.h"
@@ -75,7 +74,6 @@
 #include "core/dom/ExecutionContextTask.h"
 #include "core/dom/MainThreadTaskRunner.h"
 #include "core/dom/MutationObserver.h"
-#include "core/dom/NamedFlowCollection.h"
 #include "core/dom/NodeChildRemovalTracker.h"
 #include "core/dom/NodeFilter.h"
 #include "core/dom/NodeIterator.h"
@@ -1037,24 +1035,6 @@ bool Document::regionBasedColumnsEnabled() const
     return settings() && settings()->regionBasedColumnsEnabled();
 }
 
-PassRefPtr<DOMNamedFlowCollection> Document::webkitGetNamedFlows()
-{
-    if (!RuntimeEnabledFeatures::cssRegionsEnabled() || !renderView())
-        return 0;
-
-    updateStyleIfNeeded();
-
-    return namedFlows()->createCSSOMSnapshot();
-}
-
-NamedFlowCollection* Document::namedFlows()
-{
-    if (!m_namedFlows)
-        m_namedFlows = NamedFlowCollection::create(this);
-
-    return m_namedFlows.get();
-}
-
 PassRefPtr<Element> Document::createElementNS(const AtomicString& namespaceURI, const AtomicString& qualifiedName, ExceptionState& exceptionState)
 {
     AtomicString prefix, localName;