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

Source/core/rendering/style/RenderStyleConstants.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 479 matching lines @@
 enum TextOverflow { TextOverflowClip = 0, TextOverflowEllipsis };
 
 enum EImageRendering { ImageRenderingAuto, ImageRenderingOptimizeSpeed, ImageRenderingOptimizeQuality, ImageRenderingOptimizeContrast };
 
 enum ImageResolutionSource { ImageResolutionSpecified = 0, ImageResolutionFromImage };
 
 enum ImageResolutionSnap { ImageResolutionNoSnap = 0, ImageResolutionSnapPixels };
 
 enum Order { LogicalOrder = 0, VisualOrder };
 
-enum RegionFragment { AutoRegionFragment, BreakRegionFragment };
-
 enum ColumnAxis { HorizontalColumnAxis, VerticalColumnAxis, AutoColumnAxis };
 
 enum ColumnProgression { NormalColumnProgression, ReverseColumnProgression };
 
 enum WrapFlow { WrapFlowAuto, WrapFlowBoth, WrapFlowStart, WrapFlowEnd, WrapFlowMaximum, WrapFlowClear };
 
 enum WrapThrough { WrapThroughWrap, WrapThroughNone };
 
 enum RubyPosition { RubyPositionBefore, RubyPositionAfter };
 
@@ skipping 41 matching lines @@
 // Reasonable maximum to prevent insane font sizes from causing crashes on some platforms (such as Windows).
 static const float maximumAllowedFontSize = 1000000.0f;
 
 enum TextIndentLine { TextIndentFirstLine, TextIndentEachLine };
 
 enum LayoutBox { BoxMissing = 0, MarginBox, BorderBox, PaddingBox, ContentBox };
 
 } // namespace WebCore
 
 #endif // RenderStyleConstants_h