Incorporates feedback by Nicolas for UTF-8 bytes based scanner CL

sdk/lib/_internal/compiler/implementation/scanner/string_scanner.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.
 
 part of scanner;
 
 /**
  * Scanner that reads from a String and creates tokens that points to
  * substrings.
  */
@@ skipping 24 matching lines @@
 
   int advance() => string.codeUnitAt(++scanOffset);
   int peek() => string.codeUnitAt(scanOffset + 1);
 
   int get stringOffset => scanOffset;
 
   int currentAsUnicode(int next) => next;
 
   void handleUnicode(int startScanOffset) { }
 
-
   Token firstToken() => tokens.next;
   Token previousToken() => tail;
 
   void appendSubstringToken(PrecedenceInfo info, int start,
                             bool asciiOnly, [int extraOffset = 0]) {
     tail.next = new StringToken.fromSubstring(info, string, start,
-        scanOffset + extraOffset, tokenStart, true);
+        scanOffset + extraOffset, tokenStart, canonicalize: true);
     tail = tail.next;
   }
 }