Make hasNext a getter instead of a method.

lib/compiler/implementation/js_backend/constant_emitter.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 ConstantEmitter implements ConstantVisitor {
   final Compiler compiler;
   final Namer namer;
 
   CodeBuffer buffer;
   bool shouldEmitCanonicalVersion;
@@ skipping 73 matching lines @@
 
   /**
    * Write the contents of the quoted string to a [CodeBuffer] in
    * a form that is valid as JavaScript string literal content.
    * The string is assumed quoted by single quote characters.
    */
   void writeEscapedString(DartString string,
                           CodeBuffer buffer,
                           Node diagnosticNode) {
     Iterator<int> iterator = string.iterator();
-    while (iterator.hasNext()) {
+    while (iterator.hasNext) {
       int code = iterator.next();
       if (identical(code, $SQ)) {
         buffer.add(r"\'");
       } else if (identical(code, $LF)) {
         buffer.add(r'\n');
       } else if (identical(code, $CR)) {
         buffer.add(r'\r');
       } else if (identical(code, $LS)) {
         // This Unicode line terminator and $PS are invalid in JS string
         // literals.
@@ skipping 138 matching lines @@
       buffer.add(getJsConstructor(constant.type.element));
       buffer.add("(");
       for (int i = 0; i < constant.fields.length; i++) {
         if (i != 0) buffer.add(", ");
         _visit(constant.fields[i]);
       }
       buffer.add(")");
     }
   }
 }