Make isEmpty a getter.

lib/compiler/implementation/enqueue.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 class EnqueueTask extends CompilerTask {
   final Enqueuer codegen;
   final Enqueuer resolution;
 
   String get name => 'Enqueue';
 
@@ skipping 191 matching lines @@
     }
   }
 
   void onRegisterInstantiatedClass(ClassElement cls) {
     task.measure(() {
       // The class must be resolved to compute the set of all
       // supertypes.
       cls.ensureResolved(compiler);
 
       for (Link<DartType> supertypes = cls.allSupertypesAndSelf;
-           !supertypes.isEmpty(); supertypes = supertypes.tail) {
+           !supertypes.isEmpty; supertypes = supertypes.tail) {
         cls = supertypes.head.element;
         if (seenClasses.contains(cls)) continue;
         seenClasses.add(cls);
         cls.ensureResolved(compiler);
         if (!cls.isInterface()) {
           cls.implementation.forEachMember(processInstantiatedClassMember);
         }
         if (isResolutionQueue) {
           compiler.resolver.checkMembers(cls);
         }
@@ skipping 48 matching lines @@
     task.measure(() {
       registerNewSelector(setterName, selector, universe.invokedSetters);
     });
   }
 
   processInstanceMembers(SourceString n, bool f(Element e)) {
     String memberName = n.slowToString();
     Link<Element> members = instanceMembersByName[memberName];
     if (members != null) {
       LinkBuilder<Element> remaining = new LinkBuilder<Element>();
-      for (; !members.isEmpty(); members = members.tail) {
+      for (; !members.isEmpty; members = members.tail) {
         if (!f(members.head)) remaining.addLast(members.head);
       }
       instanceMembersByName[memberName] = remaining.toLink();
     }
   }
 
   void handleUnseenSelector(SourceString methodName, Selector selector) {
     processInstanceMembers(methodName, (Element member) {
       if (selector.applies(member, compiler)) {
         addToWorkList(member);
@@ skipping 56 matching lines @@
                           new TypedSelector(type, setter),
                           universe.fieldSetters);
     });
   }
 
   void registerIsCheck(DartType type) {
     universe.isChecks.add(type);
   }
 
   void forEach(f(WorkItem work)) {
-    while (!queue.isEmpty()) {
+    while (!queue.isEmpty) {
       f(queue.removeLast()); // TODO(kasperl): Why isn't this removeFirst?
     }
   }
 
   String toString() => 'Enqueuer($name)';
 
   registerUsedSelector(Selector selector) {
     Element interceptor = compiler.backend.getInterceptor(selector);
     if (interceptor != null) {
       registerStaticUse(interceptor);
     }
   }
 }