Remove a lot of API surface from Element.

sky/engine/core/dom/shadow/SelectRuleFeatureSet.cpp

Index: sky/engine/core/dom/shadow/SelectRuleFeatureSet.cpp
diff --git a/sky/engine/core/dom/shadow/SelectRuleFeatureSet.cpp b/sky/engine/core/dom/shadow/SelectRuleFeatureSet.cpp
index ba90bfc0add482bc34e200f0399fb386c3be1112..79af5ae1f96c06cffbf19fd21188fa9c51f34c70 100644
--- a/sky/engine/core/dom/shadow/SelectRuleFeatureSet.cpp
+++ b/sky/engine/core/dom/shadow/SelectRuleFeatureSet.cpp
@@ -38,20 +38,17 @@
 namespace blink {
 
 SelectRuleFeatureSet::SelectRuleFeatureSet()
-    : m_featureFlags(0)
 {
 }
 
 void SelectRuleFeatureSet::add(const SelectRuleFeatureSet& featureSet)
 {
     m_cssRuleFeatureSet.add(featureSet.m_cssRuleFeatureSet);
-    m_featureFlags |= featureSet.m_featureFlags;
 }
 
 void SelectRuleFeatureSet::clear()
 {
     m_cssRuleFeatureSet.clear();
-    m_featureFlags = 0;
 }
 
 void SelectRuleFeatureSet::collectFeaturesFromSelector(const CSSSelector& selector)