Add CSS conic-gradient calc() support

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

Index: third_party/WebKit/Source/core/css/parser/CSSPropertyParserHelpers.cpp
diff --git a/third_party/WebKit/Source/core/css/parser/CSSPropertyParserHelpers.cpp b/third_party/WebKit/Source/core/css/parser/CSSPropertyParserHelpers.cpp
index 53eae84f694221d69e58fba1b700446bd189bb7f..b16ebafb082b39645b4eefd28e1e608ee384f953 100644
--- a/third_party/WebKit/Source/core/css/parser/CSSPropertyParserHelpers.cpp
+++ b/third_party/WebKit/Source/core/css/parser/CSSPropertyParserHelpers.cpp
@@ -940,9 +940,12 @@ static CSSPrimitiveValue* ConsumeAngleOrPercent(CSSParserTokenRange& range,
                                                 CSSParserMode,
                                                 ValueRange value_range,
                                                 UnitlessQuirk) {
-  return range.Peek().GetType() == kPercentageToken
-             ? ConsumePercent(range, value_range)
-             : ConsumeAngle(range);
+  if (auto* css_percent = ConsumePercent(range, value_range))
+    return css_percent;
+  if (auto* css_angle = ConsumeAngle(range))
+    return css_angle;
+
+  return nullptr;
 }
 
 using PositionFunctor = CSSPrimitiveValue* (*)(CSSParserTokenRange&,