Remove CSS_REGIONS compile flag from Blink.

Source/core/css/RuleSet.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2004-2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 Nicholas Shanks (webkit@nickshanks.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007, 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
@@ skipping 313 matching lines @@
                 continue;
             const StyleRuleFontFace* fontFaceRule = static_cast<StyleRuleFontFace*>(rule);
             resolver->fontSelector()->addFontFaceRule(fontFaceRule);
             resolver->invalidateMatchedPropertiesCache();
         } else if (rule->isKeyframesRule() && resolver) {
             // FIXME (BUG 72462): We don't add @keyframe rules of scoped style sheets for the moment.
             if (scope)
                 continue;
             resolver->addKeyframeStyle(static_cast<StyleRuleKeyframes*>(rule));
         }
-#if ENABLE(CSS_REGIONS)
         else if (rule->isRegionRule() && resolver) {

[eseidel, 2013/04/30 00:11:09]

I wonder if we need to runtime guard this?

             // FIXME (BUG 72472): We don't add @-webkit-region rules of scoped style sheets for the moment.
             if (scope)
                 continue;
             addRegionRule(static_cast<StyleRuleRegion*>(rule), hasDocumentSecurityOrigin);
         }
-#endif
         else if (rule->isHostRule())
             resolver->addHostRule(static_cast<StyleRuleHost*>(rule), hasDocumentSecurityOrigin, scope);
 #if ENABLE(CSS_DEVICE_ADAPTATION)
         else if (rule->isViewportRule() && resolver) {
             // @viewport should not be scoped.
             if (scope)
                 continue;
             resolver->viewportStyleResolver()->addViewportRule(static_cast<StyleRuleViewport*>(rule));
         }
 #endif
@@ skipping 42 matching lines @@
     shrinkMapVectorsToFit(m_tagRules);
     shrinkMapVectorsToFit(m_shadowPseudoElementRules);
     m_linkPseudoClassRules.shrinkToFit();
     m_cuePseudoRules.shrinkToFit();
     m_focusPseudoClassRules.shrinkToFit();
     m_universalRules.shrinkToFit();
     m_pageRules.shrinkToFit();
 }
 
 } // namespace WebCore