Added CSSPropertyAPIMethods.json5 which defines all API methods.

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",
+                },
+
+                // - return_type
+                // Return type of this method.
+                return_type: {
+                        default: "",
+                        valid_type: "str",
+                },
+
+                // - parameters
+                // The parameters of this method. This string should be the types of
+                // all parameters, inside brackets and comma separated.
+                parameters: {
+                        default: "",
+                        valid_type: "str",
+                }
+        },
+        data: [
+                {
+                  name: "parseSingleValue",
+                  return_type: "const CSSValue*",
+                  parameters: "(CSSParserTokenRange&, const CSSParserContext*)"
+                },
+                {
+                  name: "parseShorthand",
+                  return_type: "bool",
+                  parameters: "(bool, CSSParserTokenRange&, const CSSParserContext*)"
+                },
+        ]
+}