Convert property methods into getters.

sdk/lib/_internal/compiler/implementation/dart_types.dart

Index: sdk/lib/_internal/compiler/implementation/dart_types.dart
diff --git a/sdk/lib/_internal/compiler/implementation/dart_types.dart b/sdk/lib/_internal/compiler/implementation/dart_types.dart
index 17794f9d6e79c8e6bddda99321484c5ffbf00220..5a270e91213d4825f62daca7414496f62a58a75a 100644
--- a/sdk/lib/_internal/compiler/implementation/dart_types.dart
+++ b/sdk/lib/_internal/compiler/implementation/dart_types.dart
@@ -1043,12 +1043,12 @@ abstract class AbstractTypeRelation extends DartTypeVisitor<bool, DartType> {
   bool visitTypeVariableType(TypeVariableType t, DartType s) {
     // Identity check is handled in [isSubtype].
     DartType bound = t.element.bound;
-    if (bound.element.isTypeVariable()) {
+    if (bound.element.isTypeVariable) {
       // The bound is potentially cyclic so we need to be extra careful.
       Link<TypeVariableElement> seenTypeVariables =
           const Link<TypeVariableElement>();
       seenTypeVariables = seenTypeVariables.prepend(t.element);
-      while (bound.element.isTypeVariable()) {
+      while (bound.element.isTypeVariable) {
         TypeVariableElement element = bound.element;
         if (identical(bound.element, s.element)) {
           // [t] extends [s].