Remove deprecated string features.

samples/logo/logo.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.
 
 import 'dart:html';
 import 'dart:svg';
 import 'dart:math' as Math;
 
 class Color {
   int hue;
@@ skipping 33 matching lines @@
     }
 
     return new Color((h.round() % 360).toInt(), s, l);
   }
 
   factory Color.fromHex(String hex) => new Color.rgb(
       _parseHex(hex.substring(1, 3))/255,
       _parseHex(hex.substring(3, 5))/255,
       _parseHex(hex.substring(5, 7))/255);
 
-  // This should be in the core library. Issue #233
   static int _parseHex(String hex) {
-    final codes = hex.charCodes;
-    var number = 0;
-    for (var i = 0; i < codes.length; i++) {
-      final code = codes[i];
-      var digit;
-      if (code >= 48 && code <= 57) { // 0-9
-        digit = code - 48;
-      } else if (code >= 97 && code <= 102) { // a-f
-        digit = code - 97 + 10;
-      } else {
-        throw "Invalid hex string: '$hex'";
-      }
-      number *= 16; // shift previous digits left one place
-      number += digit;
-    }
-    return number;
+    return int.parse(hex, radix: 16);
   }
 
   String get hex {
     final h = (hue % 360) / 360;
     final s = saturation;
     final l = lightness;
 
     // HSL to RGB algorithm from the CSS spec
     // http://www.w3.org/TR/css3-color/#hsl-color
     final m2 = l <= 0.5 ? l * (s + 1) : l + s - l * s;
@@ skipping 108 matching lines @@
 
   document.query("input[name=invert]").onChange.listen((Event e) {
     InputElement invert = e.target;
     if (invert.checked) {
       logo.classes = ['inverse'];
     } else {
       logo.classes = [];
     }
   });
 }