Partial implementation of CSSVariablesMap for CSS Variables CSSOM

Source/core/css/CSSStyleDeclaration.h

Index: Source/core/css/CSSStyleDeclaration.h
diff --git a/Source/core/css/CSSStyleDeclaration.h b/Source/core/css/CSSStyleDeclaration.h
index 68405ad1ca2070b7f51492f2fddacd07652a4c1b..9de0dbf205d83cd9d297f5e6fe5a647115998627 100644
--- a/Source/core/css/CSSStyleDeclaration.h
+++ b/Source/core/css/CSSStyleDeclaration.h
@@ -23,7 +23,8 @@
 
 #include "CSSPropertyNames.h"
 #include "bindings/v8/ScriptWrappable.h"
-#include <wtf/Forward.h>
+#include "wtf/Forward.h"
+#include "wtf/Vector.h"
 
 namespace WebCore {
 
@@ -31,8 +32,9 @@ class CSSProperty;
 class CSSRule;
 class CSSStyleSheet;
 class CSSValue;
+class CSSVariablesMap;
 class MutableStylePropertySet;
-class StylePropertySet;
+class VariablesIterator;
 
 typedef int ExceptionCode;
 
@@ -57,6 +59,13 @@ public:
     virtual void setProperty(const String& propertyName, const String& value, const String& priority, ExceptionCode&) = 0;
     virtual String removeProperty(const String& propertyName, ExceptionCode&) = 0;
 
+    virtual PassRefPtr<CSSVariablesMap> var() = 0;
+    virtual unsigned variableCount() const = 0;
+    virtual String variableValue(const AtomicString& name) const = 0;
+    virtual void setVariableValue(const AtomicString& name, const String& value, ExceptionCode&) = 0;
+    virtual bool removeVariable(const AtomicString& name) = 0;
+    virtual void clearVariables(ExceptionCode&) = 0;
+
     // CSSPropertyID versions of the CSSOM functions to support bindings and editing.
     // Use the non-virtual methods in the concrete subclasses when possible.
     // The CSSValue returned by this function should not be exposed to the web as it may be used by multiple documents at the same time.