Added CSSPropertyAPI and CSS padding properties which implement this API

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

+// Copyright 2016 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/CSSPropertyAPIPadding.h"
+
+#include "core/css/parser/CSSParserTokenRange.h"
+#include "core/css/parser/CSSPropertyParserHelpers.h"
+
+namespace blink {
+
+const CSSValue* CSSPropertyAPIWebkitPadding::parseSingleValue(
+    CSSParserTokenRange& range,
+    const CSSParserContext& context) {
+  return consumeLengthOrPercent(
+      range, context.mode(), ValueRangeNonNegative,
+      CSSPropertyParserHelpers::UnitlessQuirk::Forbid);
+}
+
+}  // namespace blink