Parse input argument types and store the argument types in CSSPaintDefinition.

third_party/WebKit/LayoutTests/csspaint/resources/test-runner-paint-helper.js

+// Given a set of 'tests', runs them in the worklet, then comparing the
+// expectedError or the expectedMessage.
+//
+// Usage:
+//   runner([{/* test1 */}, { /* test2 */}]);
+function runner(tests) {
+    if (window.testRunner) {
+        testRunner.waitUntilDone();
+        testRunner.dumpAsText();
+    }
+
+    tests.reduce(function(chain, obj) {
+        return chain.then(function() {
+            if (obj.expectedError) {
+                console.log('The worklet should throw an error with: "' + obj.expectedError + '"');
+            } else if (obj.expectedMessage) {
+                console.log('The worklet should log a warning with: "' + obj.expectedMessage + '"');
+            } else {
+                console.log('The worklet should not throw an error.');
+            }
+            var blob = new Blob([obj.script], {type: 'text/javascript'});
+            return paintWorklet.import(URL.createObjectURL(blob));
+        });
+    }, Promise.resolve()).then(function() {
+        if (window.testRunner) {
+            testRunner.notifyDone();
+        }
+    });
+}