Remove insertRange.

utils/tests/string_encoding/benchmark_runner.dart

Index: utils/tests/string_encoding/benchmark_runner.dart
diff --git a/utils/tests/string_encoding/benchmark_runner.dart b/utils/tests/string_encoding/benchmark_runner.dart
index de90cf5b43e21006d1a8506102f4066bf6e4344e..f29c4f994d16ea86d07a45583c2d5df6af2965d7 100644
--- a/utils/tests/string_encoding/benchmark_runner.dart
+++ b/utils/tests/string_encoding/benchmark_runner.dart
@@ -168,15 +168,13 @@ class TestReport {
   }
 
   String _leftAlign(String s, int width) {
-    List<int> outCodes = [];
-    outCodes.insertRange(0, width, spaceChar);
+    List<int> outCodes = new List<int>.filled(width, spaceChar);
     outCodes.setRange(0, Math.min(width, s.length), s.codeUnits);
     return new String.fromCharCodes(outCodes);
   }
 
   String _rightAlign(String s, int width) {
-    List<int> outCodes = [];
-    outCodes.insertRange(0, width, spaceChar);
+    List<int> outCodes = new List<int>.filled(width, spaceChar);
     int fromIndex = Math.max(0, width - s.length);
     int length = Math.min(width, s.length);
     outCodes.setRange(fromIndex, fromIndex + length, s.codeUnits);