Partial implementation of CSSVariablesMap for CSS Variables CSSOM

Source/core/css/CSSComputedStyleDeclaration.h

Index: Source/core/css/CSSComputedStyleDeclaration.h
diff --git a/Source/core/css/CSSComputedStyleDeclaration.h b/Source/core/css/CSSComputedStyleDeclaration.h
index a8526cbfd01833182d71a69ab61c563c239923bc..2eee153f8ac548e25cbddfa91f82d16a345d7390 100644
--- a/Source/core/css/CSSComputedStyleDeclaration.h
+++ b/Source/core/css/CSSComputedStyleDeclaration.h
@@ -23,7 +23,10 @@
 
 #include "core/css/CSSStyleDeclaration.h"
 #include "core/rendering/style/RenderStyleConstants.h"
+#include "wtf/HashMap.h"
 #include "wtf/RefPtr.h"
+#include "wtf/text/AtomicString.h"
+#include "wtf/text/AtomicStringHash.h"
 #include "wtf/text/WTFString.h"
 
 namespace WebCore {
@@ -97,6 +100,13 @@ private:
     virtual String getPropertyValueInternal(CSSPropertyID);
     virtual void setPropertyInternal(CSSPropertyID, const String& value, bool important, ExceptionCode&);
 
+    const HashMap<AtomicString, String>* variableMap() const;
+    virtual unsigned variableCount() const OVERRIDE;
+    virtual String variableValue(const AtomicString& name) const OVERRIDE;
+    virtual void setVariableValue(const AtomicString& name, const String& value, ExceptionCode&) OVERRIDE;
+    virtual bool removeVariable(const AtomicString& name) OVERRIDE;
+    virtual void clearVariables(ExceptionCode&) OVERRIDE;
+
     virtual bool cssPropertyMatches(CSSPropertyID, const CSSValue*) const OVERRIDE;
 
     PassRefPtr<CSSValue> valueForShadow(const ShadowData*, CSSPropertyID, const RenderStyle*) const;