[css-typed-om] replace is2D() method with attribute in CSSTransformValue.

third_party/WebKit/LayoutTests/typedcssom/cssTransformValue.html

 <!DOCTYPE html>
 <script src="../resources/testharness.js"></script>
 <script src="../resources/testharnessreport.js"></script>
 
 <script>
 
 test(function() {
   var transformValueObject = new CSSTransformValue();
     assert_equals(transformValueObject.constructor.name, CSSTransformValue.name);
 }, "A CSSTransformValue object can be constructed");
 
 test(function() {
   var transformArray = [new CSSScale(2,2),
     new CSSMatrixComponent(1,1,1,1,1,1), new CSSScale(5,6)];
   var transformValue = new CSSTransformValue(transformArray);
-  assert_true(transformValue.is2D());
+  assert_true(transformValue.is2D);
 }, "is2D returns true for transformValues containing only 2D transformComponents");
 
 test(function() {
   var transformArray = [new CSSScale(2,2),
     new CSSMatrixComponent(1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1), new CSSScale(5,6)];
   var transformValue = new CSSTransformValue(transformArray);
-  assert_false(transformValue.is2D());
+  assert_false(transformValue.is2D);
 }, "is2D returns false for transformValues containing both 2D and 3D transformComponents");
 
 test(function() {
   var transformArray = [new CSSScale(2,2),
     new CSSMatrixComponent(1,1,1,1,1,1), new CSSScale(5,6)];
   var transformValue = new CSSTransformValue(transformArray);
 
   var newTransformArray = [];
   for (var component of transformValue) {
     newTransformArray.push(component);
   }
   assert_true(newTransformArray.length == 3);
   assert_equals(newTransformArray[0].constructor.name, CSSScale.name);
   assert_equals(newTransformArray[1].constructor.name, CSSMatrixComponent.name);
   assert_equals(newTransformArray[2].constructor.name, CSSScale.name);
 }, "CSSTransformValue can iterate through all its all its transformComponent members");
 
 </script>
 
 <body>
 </body>