Implement fromEnvironment on bool, int and String

runtime/lib/integers_patch.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.
 // Dart core library.
 
 // VM implementation of int.
 
 patch class int {
 
   static bool _isWhitespace(int codePoint) {
@@ skipping 69 matching lines @@
         if (onError == null) {
           throw new FormatException(source);
         }
         return onError(source);
       }
       return result;
     }
     return _slowParse(source, radix, onError);
   }
 
+  /* patch */ const factory int.fromEnvironment(String name,
+                                                {int defaultValue})
+      native "Integer_fromEnvironment";
+
   static int _slowParse(String source, int radix, int onError(String str)) {
     if (source is! String) throw new ArgumentError(source);
     if (radix is! int) throw new ArgumentError("Radix is not an integer");
     if (radix < 2 || radix > 36) {
       throw new RangeError("Radix $radix not in range 2..36");
     }
     if (onError == null) {
       onError = _throwFormatException;
     }
     // Remove leading and trailing white space.
@@ skipping 27 matching lines @@
       int digit = digits[code - 0x30];
       if (digit >= radix) return onError(source);
       result = result * radix + digit;
       i++;
       if (i == source.length) break;
       code = source.codeUnitAt(i);
     } while (true);
     return negative ? -result : result;
   }
 }