Clean sort_helper.dart a bit: remove printing.

tests/corelib/sort_helper.dart

 // Copyright (c) 2011, 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 SortHelper {
 
   SortHelper(this.sortFunction, this.compareFunction) {}
 
   void run() {
     testSortIntLists();
     testSortDoubleLists();
   }
 
-  void printList(List a) {
-    StringBuffer buffer = new StringBuffer();
-    for (int i = 0; i < a.length; i++) {
-      if (i != 0) buffer.add(",");
-      buffer.add(a[i]);
-    }
-    print("[$buffer]");
-  }
-
   bool isSorted(List a) {
     for (int i = 1; i < a.length; i++) {
       if (compareFunction(a[i - 1], a[i]) > 0) {
         return false;
       }
     }
     return true;
   }
 
   void testSortIntLists() {
@@ skipping 82 matching lines @@
     testInsertionSort(2, 3, 0, 1);
     testInsertionSort(3, 0, 1, 2);
     testInsertionSort(3, 0, 2, 1);
     testInsertionSort(3, 1, 2, 0);
     testInsertionSort(3, 1, 0, 2);
     testInsertionSort(3, 2, 1, 0);
     testInsertionSort(3, 2, 0, 1);
   }
 
   void testSort(List a) {
-    final bool log = false;
-    if (log) printList(a);
     sortFunction(a);
-    if (log) printList(a);
-    bool sorted = isSorted(a);
-    Expect.equals(true, sorted);
-    if (log) print(sorted);
+    Expect.isTrue(isSorted(a));
   }
 
   void testInsertionSort(int i1, int i2, int i3, int i4) {
     var a = new List(4);
     a[0] = i1;
     a[1] = i2;
     a[2] = i3;
     a[3] = i4;
     testSort(a);
   }
@@ skipping 12 matching lines @@
 
     for (int i = 0; i < a.length; i++) {
       a[i] = 1.5;
     }
     testSort(a);
   }
 
   Function sortFunction;
   Function compareFunction;
 }