Remove CSS_REGIONS compile flag from Blink.

Source/core/rendering/RenderNamedFlowThread.cpp

 /*
  * Copyright (C) 2012 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 26 matching lines @@
 #include "core/rendering/InlineTextBox.h"
 #include "core/rendering/RenderInline.h"
 #include "core/rendering/RenderRegion.h"
 #include "core/rendering/RenderText.h"
 #include "core/rendering/RenderView.h"
 
 namespace WebCore {
 
 RenderNamedFlowThread* RenderNamedFlowThread::createAnonymous(Document* document, PassRefPtr<NamedFlow> namedFlow)
 {
-    ASSERT(document->cssRegionsEnabled());
+    ASSERT(RuntimeEnabledFeatures::cssRegionsEnabled());
     RenderNamedFlowThread* renderer = new (document->renderArena()) RenderNamedFlowThread(namedFlow);
     renderer->setDocumentForAnonymous(document);
     return renderer;
 }
 
 RenderNamedFlowThread::RenderNamedFlowThread(PassRefPtr<NamedFlow> namedFlow)
     : m_namedFlow(namedFlow)
     , m_regionLayoutUpdateEventTimer(this, &RenderNamedFlowThread::regionLayoutUpdateEventTimerFired)
 {
 }
@@ skipping 545 matching lines @@
                     lastEndNode = node;
                 }
             }
         }
         if (foundStartPosition || skipOverOutsideNodes)
             rangeObjects.append(range);
     }
 }
 
 }