Remove some unused functions in core

Source/core/css/CSSPropertySourceData.h

Index: Source/core/css/CSSPropertySourceData.h
diff --git a/Source/core/css/CSSPropertySourceData.h b/Source/core/css/CSSPropertySourceData.h
index e2452b05993eae0ebce0913617a113b0e8f4e301..dba18e12a64177ae7a865a750e5b64eb21fb5831 100644
--- a/Source/core/css/CSSPropertySourceData.h
+++ b/Source/core/css/CSSPropertySourceData.h
@@ -57,10 +57,6 @@ struct CSSPropertySourceData {
 public:
     CSSPropertySourceData(const String& name, const String& value, bool important, bool disabled, bool parsedOk, const SourceRange& range);
     CSSPropertySourceData(const CSSPropertySourceData& other);
-    CSSPropertySourceData();
-
-    String toString() const;
-    unsigned hash() const;
 
     void trace(Visitor* visitor) { visitor->trace(range); }