Added CSSPropertyBorderImageUtils which holds shared parsing logic.

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

Index: third_party/WebKit/Source/core/css/properties/CSSPropertyBorderImageUtils.h
diff --git a/third_party/WebKit/Source/core/css/properties/CSSPropertyBorderImageUtils.h b/third_party/WebKit/Source/core/css/properties/CSSPropertyBorderImageUtils.h
new file mode 100644
index 0000000000000000000000000000000000000000..d68e627f6561001b983737c58902a8db204f3105
--- /dev/null
+++ b/third_party/WebKit/Source/core/css/properties/CSSPropertyBorderImageUtils.h
@@ -0,0 +1,38 @@
+// 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 CSSPropertyBorderImageUtils_h
+#define CSSPropertyBorderImageUtils_h
+
+#include "platform/wtf/Allocator.h"
+
+namespace blink {
+
+class CSSParserContext;
+class CSSParserTokenRange;
+class CSSValue;
+
+class CSSPropertyBorderImageUtils {
+  STATIC_ONLY(CSSPropertyBorderImageUtils);
+
+  static CSSValue* ConsumeWebkitBorderImage(CSSParserTokenRange&,
+                                            const CSSParserContext*);
+  static bool ConsumeBorderImageComponents(CSSParserTokenRange&,
+                                           const CSSParserContext*,
+                                           CSSValue*& source,
+                                           CSSValue*& slice,
+                                           CSSValue*& width,
+                                           CSSValue*& outset,
+                                           CSSValue*& repeat,
+                                           bool default_fill);
+  static CSSValue* ConsumeBorderImageRepeat(CSSParserTokenRange&);
+  static CSSValue* ConsumeBorderImageSlice(CSSParserTokenRange&,
+                                           bool default_fill);
+  static CSSValue* ConsumeBorderImageWidth(CSSParserTokenRange&);
+  static CSSValue* ConsumeBorderImageOutset(CSSParserTokenRange&);
+};
+
+}  // namespace blink
+
+#endif  // CSSPropertyBorderImageUtils_h