Change Counter to be a CSSValue

Source/core/css/CSSCounterValue.cpp

Index: Source/core/css/CSSCounterValue.cpp
diff --git a/Source/core/css/CSSCounterValue.cpp b/Source/core/css/CSSCounterValue.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..6a1f0698768175dd1086da613b091acc7504ae67
--- /dev/null
+++ b/Source/core/css/CSSCounterValue.cpp
@@ -0,0 +1,44 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "config.h"
+#include "core/css/CSSCounterValue.h"
+
+#include "core/css/CSSMarkup.h"
+#include "wtf/text/StringBuilder.h"
+
+namespace blink {
+
+String CSSCounterValue::customCSSText() const
+{
+    StringBuilder result;
+    if (separator().isEmpty())
+        result.appendLiteral("counter(");
+    else
+        result.appendLiteral("counters(");
+
+    result.append(identifier());
+    if (!separator().isEmpty()) {
+        result.appendLiteral(", ");
+        result.append(serializeString(separator()));
+    }
+    bool isDefaultListStyle = listStyleIdent() == CSSValueDecimal;
+    if (!listStyle().isEmpty() && !isDefaultListStyle) {
+        result.appendLiteral(", ");
+        result.append(listStyle());
+    }
+    result.append(')');
+
+    return result.toString();
+}
+
+DEFINE_TRACE_AFTER_DISPATCH(CSSCounterValue)
+{
+    visitor->trace(m_identifier);
+    visitor->trace(m_listStyle);
+    visitor->trace(m_separator);
+    CSSValue::traceAfterDispatch(visitor);
+}
+
+}