[CSS Typed OM] Refactor is2D handling in CSSTransformComponents to match new spec

third_party/WebKit/LayoutTests/typedcssom/cssSkew.html

Index: third_party/WebKit/LayoutTests/typedcssom/cssSkew.html
diff --git a/third_party/WebKit/LayoutTests/typedcssom/cssSkew.html b/third_party/WebKit/LayoutTests/typedcssom/cssSkew.html
index c7375e5d68206dd792fe5bda6a87232940a33359..e8b3db139aedee27d8fab30a3b18548145074f54 100644
--- a/third_party/WebKit/LayoutTests/typedcssom/cssSkew.html
+++ b/third_party/WebKit/LayoutTests/typedcssom/cssSkew.html
@@ -68,7 +68,7 @@ for (let params of testParams) {
 
 for (let params of testParams) {
   test(() => {
-    assert_true(params.input.is2D());
+    assert_true(params.input.is2D);
   }, "is2D value is correct for " + params.cssText);
 }
 
@@ -130,4 +130,14 @@ for (let a of ['ax', 'ay']) {
   }, "Setting " + a + " with invalid values");
 }
 
+test(() => {
+  let skew = new CSSSkew(
+      new CSSUnitValue(1, 'deg'), new CSSUnitValue(2, 'deg'));
+  assert_true(skew.is2D);
+
+  skew.is2D = false;
+
+  assert_true(skew.is2D);
+}, "Setting is2D does nothing");
+
 </script>