CSS Motion Path: offset-shorthand requires path before distance rotation

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 5699293aa7e0a0b411da7347ea41060f60caf947..41fc5a985bd8028d2567546cc057b5c911ff4f82 100644
--- a/third_party/WebKit/Source/core/css/parser/CSSPropertyParser.cpp
+++ b/third_party/WebKit/Source/core/css/parser/CSSPropertyParser.cpp
@@ -1605,6 +1605,36 @@ CSSValue* consumeOffsetPosition(CSSParserTokenRange& range,
   return consumePosition(range, cssParserMode, UnitlessQuirk::Forbid);
 }
 
+// offset: <offset-path> [ <offset-distance>? && <offset-rotation>? ]
+bool CSSPropertyParser::consumeOffsetShorthand(bool important) {
+  const CSSValue* offsetPath = consumePathOrNone(m_range);
+  if (!offsetPath)
+    return false;
+
+  const CSSValue* offsetRotation = consumeOffsetRotation(m_range);
+  const CSSValue* offsetDistance =
+      consumeLengthOrPercent(m_range, m_context.mode(), ValueRangeAll);
+  if (offsetDistance && !offsetRotation)
+    offsetRotation = consumeOffsetRotation(m_range);
+
+  addProperty(CSSPropertyOffsetPath, CSSPropertyOffset, *offsetPath, important);
+  addProperty(CSSPropertyOffsetDistance, CSSPropertyOffset,
+              offsetDistance ? *offsetDistance
+                             : *CSSPrimitiveValue::create(
+                                   0, CSSPrimitiveValue::UnitType::Pixels),
+              important);
+
+  if (!offsetRotation) {
+    CSSValueList* list = CSSValueList::createSpaceSeparated();
+    list->append(*CSSIdentifierValue::create(CSSValueAuto));
+    offsetRotation = list;
+  }
+  addProperty(CSSPropertyOffsetRotation, CSSPropertyOffset, *offsetRotation,
+              important);
+
+  return m_range.atEnd();
+}
+
 static CSSValue* consumeTextEmphasisStyle(CSSParserTokenRange& range) {
   CSSValueID id = range.peek().id();
   if (id == CSSValueNone)
@@ -5067,7 +5097,7 @@ bool CSSPropertyParser::parseShorthand(CSSPropertyID unresolvedProperty,
     case CSSPropertyMotion:
       return consumeShorthandGreedily(motionShorthand(), important);
     case CSSPropertyOffset:
-      return consumeShorthandGreedily(offsetShorthand(), important);
+      return consumeOffsetShorthand(important);
     case CSSPropertyWebkitTextEmphasis:
       return consumeShorthandGreedily(webkitTextEmphasisShorthand(), important);
     case CSSPropertyOutline: