*** DO NOT LAND *** Attempt to understand Regions complexity

Source/core/css/resolver/ScopedStyleResolver.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2012 Google 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.
@@ skipping 72 matching lines @@
     for (size_t i = 0; i < m_authorStyleSheets.size(); ++i)
         features.add(m_authorStyleSheets[i]->contents()->ruleSet().features());
 }
 
 void ScopedStyleResolver::resetAuthorStyle()
 {
     m_authorStyleSheets.clear();
     m_keyframesRuleMap.clear();
 }
 
-bool ScopedStyleResolver::checkRegionStyle(Element* regionElement)
-{
-    for (size_t i = 0; i < m_authorStyleSheets.size(); ++i) {
-        const RuleSet& ruleSet = m_authorStyleSheets[i]->contents()->ruleSet();
-        for (unsigned i = 0; i < ruleSet.m_regionSelectorsAndRuleSets.size(); ++i) {
-            ASSERT(ruleSet.m_regionSelectorsAndRuleSets.at(i).ruleSet.get());
-            if (checkRegionSelector(ruleSet.m_regionSelectorsAndRuleSets.at(i).selector, regionElement))
-                return true;
-        }
-    }
-    return false;
-}
-
 const StyleRuleKeyframes* ScopedStyleResolver::keyframeStylesForAnimation(const StringImpl* animationName)
 {
     if (m_keyframesRuleMap.isEmpty())
         return 0;
 
     KeyframesRuleMap::iterator it = m_keyframesRuleMap.find(animationName);
     if (it == m_keyframesRuleMap.end())
         return 0;
 
     return it->value.get();
@@ skipping 23 matching lines @@
 
     if (m_scopingNode.isShadowRoot()) {
         scopingNode = toShadowRoot(m_scopingNode).host();
         behaviorAtBoundary |= SelectorChecker::ScopeIsShadowHost;
     }
 
     RuleRange ruleRange = collector.matchedResult().ranges.authorRuleRange();
     for (size_t i = 0; i < m_authorStyleSheets.size(); ++i) {
         MatchRequest matchRequest(&m_authorStyleSheets[i]->contents()->ruleSet(), includeEmptyRules, scopingNode, applyAuthorStyles, i, m_authorStyleSheets[i]);
         collector.collectMatchingRules(matchRequest, ruleRange, static_cast<SelectorChecker::BehaviorAtBoundary>(behaviorAtBoundary), cascadeScope, cascadeOrder);
-        collector.collectMatchingRulesForRegion(matchRequest, ruleRange, static_cast<SelectorChecker::BehaviorAtBoundary>(behaviorAtBoundary), cascadeScope, cascadeOrder);
     }
 }
 
 void ScopedStyleResolver::matchPageRules(PageRuleCollector& collector)
 {
     // Only consider the global author RuleSet for @page rules, as per the HTML5 spec.
     ASSERT(m_scopingNode.isDocumentNode());
     for (size_t i = 0; i < m_authorStyleSheets.size(); ++i)
         collector.matchPageRules(&m_authorStyleSheets[i]->contents()->ruleSet());
 }
 
 void ScopedStyleResolver::collectViewportRulesTo(StyleResolver* resolver) const
 {
     if (!m_scopingNode.isDocumentNode())
         return;
     for (size_t i = 0; i < m_authorStyleSheets.size(); ++i)
         resolver->viewportStyleResolver()->collectViewportRules(&m_authorStyleSheets[i]->contents()->ruleSet(), ViewportStyleResolver::AuthorOrigin);
 }
 
 } // namespace WebCore