Added CSSPropertyAPI and CSS padding properties which implement this API

third_party/WebKit/Source/core/css/parser/CSSPropertyParser.cpp

Index: third_party/WebKit/Source/core/css/parser/CSSPropertyParser.cpp
diff --git a/third_party/WebKit/Source/core/css/parser/CSSPropertyParser.cpp b/third_party/WebKit/Source/core/css/parser/CSSPropertyParser.cpp
index cb27b6b55f89c8eb1707cfce2d21562dcd142272..06ba6a774ad9503b07ee0091b5fddb2d3ef203b6 100644
--- a/third_party/WebKit/Source/core/css/parser/CSSPropertyParser.cpp
+++ b/third_party/WebKit/Source/core/css/parser/CSSPropertyParser.cpp
@@ -40,6 +40,8 @@
 #include "core/css/parser/CSSParserIdioms.h"
 #include "core/css/parser/CSSPropertyParserHelpers.h"
 #include "core/css/parser/CSSVariableParser.h"
+#include "core/css/properties/CSSPaddingProperties.h"
+#include "core/css/properties/CSSPropertyDescriptor.h"
 #include "core/frame/UseCounter.h"
 #include "core/layout/LayoutTheme.h"
 #include "core/svg/SVGPathUtilities.h"
@@ -3425,6 +3427,11 @@ const CSSValue* CSSPropertyParser::parseSingleValue(
                                   m_range.peek().id());
     return consumeIdent(m_range);
   }
+
+  const CSSPropertyDescriptor& cssPropertyDesc = get(property);
+  if (cssPropertyDesc.isValidProperty)
+    return cssPropertyDesc.parseSingleValue(m_range, m_context);
+
   switch (property) {
     case CSSPropertyWillChange:
       return consumeWillChange(m_range);
@@ -3515,13 +3522,6 @@ const CSSValue* CSSPropertyParser::parseSingleValue(
       return consumeLengthOrPercent(m_range, m_context.mode(),
                                     ValueRangeNonNegative,
                                     UnitlessQuirk::Allow);
-    case CSSPropertyWebkitPaddingStart:
-    case CSSPropertyWebkitPaddingEnd:
-    case CSSPropertyWebkitPaddingBefore:
-    case CSSPropertyWebkitPaddingAfter:
-      return consumeLengthOrPercent(m_range, m_context.mode(),
-                                    ValueRangeNonNegative,
-                                    UnitlessQuirk::Forbid);
     case CSSPropertyClip:
       return consumeClip(m_range, m_context.mode());
     case CSSPropertyTouchAction: