Add a WebDocument::watchCssSelectors(selectors)

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 0e53805164613484c857d224732913b6a37ca5c6..fbb2906acf2a3080efad3e04e56a6f856169ecc5 100644
--- a/Source/core/css/resolver/StyleResolverState.h
+++ b/Source/core/css/resolver/StyleResolverState.h
@@ -38,6 +38,7 @@ namespace WebCore {
 
 class FontDescription;
 class RenderRegion;
+class StyleRule;
 
 // ElementResolveContext is immutable and serves as an input to the style resolve process.
 class ElementResolveContext {
@@ -92,6 +93,7 @@ public:
     , m_lineHeightValue(0)
     , m_fontDirty(false)
     , m_styleMap(*this, m_elementStyleResources)
+    , m_rule(0)
     { }
 
     // These are all just pass-through methods to ElementResolveContext.
@@ -113,6 +115,9 @@ public:
 
     const RenderRegion* regionForStyling() const { return m_regionForStyling; }
 
+    void setRule(StyleRule* rule) { m_rule = rule; }
+    const StyleRule* rule() const { return m_rule; }
+
     // 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).
@@ -212,8 +217,9 @@ private:
     // CSSToStyleMap is a pure-logic class and only contains
     // a back-pointer to this object.
     CSSToStyleMap m_styleMap;
-};
 
+    StyleRule* m_rule;
+};
 } // namespace WebCore
 
 #endif // StyleResolverState_h