Change new List(n) to return fixed length list.

sdk/lib/utf/utf8.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.
 
 part of dart.utf;
 
 const int _UTF8_ONE_BYTE_MAX = 0x7f;
 const int _UTF8_TWO_BYTE_MAX = 0x7ff;
 const int _UTF8_THREE_BYTE_MAX = 0xffff;
 
@@ skipping 68 matching lines @@
       encodedLength++;
     } else if (value <= _UTF8_TWO_BYTE_MAX) {
       encodedLength += 2;
     } else if (value <= _UTF8_THREE_BYTE_MAX) {
       encodedLength += 3;
     } else if (value <= UNICODE_VALID_RANGE_MAX) {
       encodedLength += 4;
     }
   }
 
-  List<int> encoded = new List<int>.fixedLength(encodedLength);
+  List<int> encoded = new List<int>(encodedLength);
   int insertAt = 0;
   for (int value in source) {
     if (value < 0 || value > UNICODE_VALID_RANGE_MAX) {
       encoded.setRange(insertAt, 3, [0xef, 0xbf, 0xbd]);
       insertAt += 3;
     } else if (value <= _UTF8_ONE_BYTE_MAX) {
       encoded[insertAt] = value;
       insertAt++;
     } else if (value <= _UTF8_TWO_BYTE_MAX) {
       encoded[insertAt] = _UTF8_FIRST_BYTE_OF_TWO_BASE | (
@@ skipping 66 matching lines @@
 
   Utf8Decoder._fromListRangeIterator(_ListRange source, [
       this.replacementCodepoint =
       UNICODE_REPLACEMENT_CHARACTER_CODEPOINT]) :
       utf8EncodedBytesIterator = source.iterator;
 
   /** Decode the remaininder of the characters in this decoder
     * into a [List<int>].
     */
   List<int> decodeRest() {
-    List<int> codepoints = new List<int>.fixedLength(utf8EncodedBytesIterator.remaining);
+    List<int> codepoints = new List<int>(utf8EncodedBytesIterator.remaining);
     int i = 0;
     while (moveNext()) {
       codepoints[i++] = current;
     }
     if (i == codepoints.length) {
       return codepoints;
     } else {
-      List<int> truncCodepoints = new List<int>.fixedLength(i);
+      List<int> truncCodepoints = new List<int>(i);
       truncCodepoints.setRange(0, i, codepoints);
       return truncCodepoints;
     }
   }
 
   int get current => _current;
 
   bool moveNext() {
     _current = null;
 
@@ skipping 71 matching lines @@
       return true;
     } else if (replacementCodepoint != null) {
       _current = replacementCodepoint;
       return true;
     } else {
       throw new ArgumentError(
           "Invalid UTF8 at ${utf8EncodedBytesIterator.position - j}");
     }
   }
 }