Revert of Changed CSSParserContext argument from * to & for null safety.

third_party/WebKit/Source/core/css/properties/CSSPropertyAPIMethods.json5

 {
   // This file specifies all the methods in CSSPropertyAPI.h and the necessary
   // information for code generation of the API and it's related classes.
   parameters: {
     // - name
     // The name of this method in camel case.
     name: {
       default: "",
       valid_type: "str",
     },
@@ skipping 18 matching lines @@
     // placed in the code above the method definition in CSSPropertyAPI.h.
     description: {
       default: "",
       valid_type: "str",
     },
   },
   data: [
     {
       name: "parseSingleValue",
       return_type: "const CSSValue*",
-      parameters: "(CSSParserTokenRange&, const CSSParserContext&)",
+      parameters: "(CSSParserTokenRange&, const CSSParserContext*)",
       description: "Parses a single CSS property and returns the corresponding CSSValue. If the input is invalid it returns nullptr.",
     },
     {
       name: "parseShorthand",
       return_type: "bool",
       parameters: "(bool, CSSParserTokenRange&, const CSSParserContext*)",
       description: "Returns true if the property can be parsed as a shorthand.",
     },
   ]
 }