Simplify watched selector handling and remove remnants of user stylesheets

Source/core/css/resolver/StyleResolverState.h

Index: Source/core/css/resolver/StyleResolverState.h
diff --git a/Source/core/css/resolver/StyleResolverState.h b/Source/core/css/resolver/StyleResolverState.h
index 35dd2a24af2323e9408c6b2dc8d90d8a4bd0ffb3..fb44e6f2fda6eaa866195d0119cffcf4e1efbeed 100644
--- a/Source/core/css/resolver/StyleResolverState.h
+++ b/Source/core/css/resolver/StyleResolverState.h
@@ -76,9 +76,6 @@ public:
     const RenderStyle* parentStyle() const { return m_parentStyle.get(); }
     RenderStyle* parentStyle() { return m_parentStyle.get(); }
 
-    void setCurrentRule(StyleRule* currentRule) { m_currentRule = currentRule; }
-    const StyleRule* currentRule() const { return m_currentRule; }
-
     // FIXME: These are effectively side-channel "out parameters" for the various
     // map functions. When we map from CSS to style objects we use this state object
     // to track various meta-data about that mapping (e.g. if it's cache-able).
@@ -163,8 +160,6 @@ private:
     // a back-pointer to this object.
     CSSToStyleMap m_styleMap;
     Vector<AtomicString> m_contentAttrValues;
-
-    RawPtrWillBeMember<StyleRule> m_currentRule;
 };
 
 } // namespace blink