Catch up the spec update in CSS Rhythmic Sizing

third_party/WebKit/Source/core/css/properties/CSSPropertyAPILineHeightStep.cpp

Index: third_party/WebKit/Source/core/css/properties/CSSPropertyAPILineHeightStep.cpp
diff --git a/third_party/WebKit/Source/core/css/properties/CSSPropertyAPILineHeightStep.cpp b/third_party/WebKit/Source/core/css/properties/CSSPropertyAPILineHeightStep.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..130c513d3b1a7a37a05594196827c623bd3bc4f1
--- /dev/null
+++ b/third_party/WebKit/Source/core/css/properties/CSSPropertyAPILineHeightStep.cpp
@@ -0,0 +1,20 @@
+// 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.
+
+#include "core/css/properties/CSSPropertyAPILineHeightStep.h"
+
+#include "core/css/CSSValueList.h"
+#include "core/css/parser/CSSParserContext.h"
+#include "core/css/parser/CSSPropertyParserHelpers.h"
+
+namespace blink {
+
+const CSSValue* CSSPropertyAPILineHeightStep::parseSingleValue(
+    CSSParserTokenRange& range,
+    const CSSParserContext* context) {
+  return CSSPropertyParserHelpers::consumeLength(range, context->mode(),
+                                                 ValueRangeNonNegative);
+}
+
+}  // namespace blink