Make isEmpty a getter.

lib/compiler/implementation/code_buffer.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 CodeBuffer implements StringBuffer {
   StringBuffer buffer;
   List<CodeBufferMarker> markers;
   int lastBufferOffset = 0;
   int mappedRangeCounter = 0;
 
   CodeBuffer()
       : buffer = new StringBuffer(),
         markers = new List<CodeBufferMarker>();
 
   int get length => buffer.length;
 
-  bool isEmpty() {
-    return buffer.isEmpty();
+  bool get isEmpty {
+    return buffer.isEmpty;
   }
 
   /**
    * Converts [object] to a string and adds it to the buffer. If [object] is a
    * [CodeBuffer], adds its markers to [markers].
    */
   CodeBuffer add(var object) {
     if (object is CodeBuffer) {
       return addBuffer(object);
     }
@@ skipping 62 matching lines @@
     });
   }
 }
 
 class CodeBufferMarker {
   final int offsetDelta;
   final sourcePosition;
 
   CodeBufferMarker(this.offsetDelta, this.sourcePosition);
 }