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

Source/core/css/resolver/StyleResolver.h

Index: Source/core/css/resolver/StyleResolver.h
diff --git a/Source/core/css/resolver/StyleResolver.h b/Source/core/css/resolver/StyleResolver.h
index c30f5a130ae7c4e7e545366d59c5e01bcbd08a6f..df3ff7590b26c63199eead2600235c9f804be5af 100644
--- a/Source/core/css/resolver/StyleResolver.h
+++ b/Source/core/css/resolver/StyleResolver.h
@@ -61,7 +61,6 @@ class KeyframeList;
 class KeyframeValue;
 class MediaQueryEvaluator;
 class MediaQueryResult;
-class RenderRegion;
 class RuleData;
 class Settings;
 class StyleKeyframe;
@@ -117,7 +116,7 @@ public:
     void popParentShadowRoot(const ShadowRoot&);
 
     PassRefPtr<RenderStyle> styleForElement(Element*, RenderStyle* parentStyle = 0, StyleSharingBehavior = AllowStyleSharing,
-        RuleMatchingBehavior = MatchAllRules, RenderRegion* regionForStyling = 0);
+        RuleMatchingBehavior = MatchAllRules);
 
     // FIXME: keyframeStylesForAnimation is only used in the legacy animations implementation
     // and should be removed when that is replaced by Web Animations.
@@ -192,9 +191,6 @@ public:
     bool hasViewportDependentMediaQueries() const { return !m_viewportDependentMediaQueryResults.isEmpty(); }
     bool mediaQueryAffectedByViewportChange() const;
 
-    // FIXME: Regions should not require special logic in StyleResolver.
-    bool checkRegionStyle(Element* regionElement);
-
     // FIXME: Rename to reflect the purpose, like didChangeFontSize or something.
     void invalidateMatchedPropertiesCache();
 
@@ -333,20 +329,6 @@ private:
     unsigned m_accessCount;
 };
 
-inline bool checkRegionSelector(const CSSSelector* regionSelector, Element* regionElement)
-{
-    if (!regionSelector || !regionElement)
-        return false;
-
-    SelectorChecker selectorChecker(regionElement->document(), SelectorChecker::QueryingRules);
-    for (const CSSSelector* s = regionSelector; s; s = CSSSelectorList::next(s)) {
-        SelectorChecker::SelectorCheckingContext selectorCheckingContext(s, regionElement, SelectorChecker::VisitedMatchDisabled);
-        if (selectorChecker.match(selectorCheckingContext, DOMSiblingTraversalStrategy()) == SelectorChecker::SelectorMatches)
-            return true;
-    }
-    return false;
-}
-
 } // namespace WebCore
 
 #endif // StyleResolver_h