Added CSSPropertyCounterUtils which holds shared counter parsing logic.

third_party/WebKit/Source/core/css/properties/CSSPropertyCounterUtils.h

+// Copyright 2017 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.
+
+#ifndef CSSPropertyCounterUtils_h
+#define CSSPropertyCounterUtils_h
+
+#include "wtf/Allocator.h"
+
+namespace blink {
+
+class CSSParserTokenRange;
+class CSSValue;
+
+class CSSPropertyCounterUtils {
+  STATIC_ONLY(CSSPropertyCounterUtils);
+
+  static const int kResetDefaultValue = 0;
+  static const int kIncrementDefaultValue = 1;
+
+  static CSSValue* consumeCounter(CSSParserTokenRange&, int);
+};
+
+}  // namespace blink
+
+#endif  // CSSPropertyCounterUtils_h