Remove CSS_REGIONS compile flag from Blink.

Source/core/css/CSSRule.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * (C) 2002-2003 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2002, 2005, 2006, 2007, 2012 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 19 matching lines @@
 namespace WebCore {
 
 struct SameSizeAsCSSRule : public RefCounted<SameSizeAsCSSRule> {
     virtual ~SameSizeAsCSSRule();
     unsigned char bitfields;
     void* pointerUnion;
 };
 
 COMPILE_ASSERT(sizeof(CSSRule) == sizeof(SameSizeAsCSSRule), CSSRule_should_stay_small);
 
-#if ENABLE(CSS_REGIONS)
 COMPILE_ASSERT(StyleRuleBase::Region == static_cast<StyleRuleBase::Type>(CSSRule::WEBKIT_REGION_RULE), enums_should_match);
-#endif
 
 #if ENABLE(CSS_DEVICE_ADAPTATION)
 COMPILE_ASSERT(StyleRuleBase::Viewport == static_cast<StyleRuleBase::Type>(CSSRule::WEBKIT_VIEWPORT_RULE), enums_should_match);
 #endif
 
 void CSSRule::setCssText(const String& /*cssText*/, ExceptionCode& /*ec*/)
 {
     notImplemented();
 }
 
 void CSSRule::reportMemoryUsage(MemoryObjectInfo* memoryObjectInfo) const
 {
     MemoryClassInfo info(memoryObjectInfo, this, WebCoreMemoryTypes::CSS);
     if (m_parentIsRule)
         info.addMember(m_parentRule, "parentRule");
     else
         info.addMember(m_parentStyleSheet, "parentStyleSheet");
 }
 
 const CSSParserContext& CSSRule::parserContext() const
 {
     CSSStyleSheet* styleSheet = parentStyleSheet();
     return styleSheet ? styleSheet->contents()->parserContext() : strictCSSParserContext();
 }
 
 } // namespace WebCore