Stop working around issue 12780 in pkg/http.

pkg/http/lib/src/utils.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.
 
 library utils;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 import 'dart:typed_data';
@@ skipping 18 matching lines @@
   return map;
 }
 
 /// Converts a [Map] from parameter names to values to a URL query string.
 ///
 ///     mapToQuery({"foo": "bar", "baz": "bang"});
 ///     //=> "foo=bar&baz=bang"
 String mapToQuery(Map<String, String> map, {Encoding encoding}) {
   var pairs = <List<String>>[];
   map.forEach((key, value) =>
-      pairs.add([urlEncode(key, encoding: encoding),
-                 urlEncode(value, encoding: encoding)]));
+      pairs.add([Uri.encodeQueryComponent(key, encoding: encoding),
+                 Uri.encodeQueryComponent(value, encoding: encoding)]));
   return pairs.map((pair) => "${pair[0]}=${pair[1]}").join("&");
 }
 
-// TODO(nweiz): get rid of this when issue 12780 is fixed.
-/// URL-encodes [source] using [encoding].
-String urlEncode(String source, {Encoding encoding}) {
-  if (encoding == null) encoding = UTF8;
-  return encoding.encode(source).map((byte) {
-    // Convert spaces to +, like encodeQueryComponent.
-    if (byte == 0x20) return '+';
-    // Pass through digits.
-    if ((byte >= 0x30 && byte < 0x3A) ||
-        // Pass through uppercase letters.
-        (byte >= 0x41 && byte < 0x5B) ||
-        // Pass through lowercase letters.
-        (byte >= 0x61 && byte < 0x7B) ||
-        // Pass through `-._~`.
-        (byte == 0x2D || byte == 0x2E || byte == 0x5F || byte == 0x7E)) {
-      return new String.fromCharCode(byte);
-    }
-    return '%' + byte.toRadixString(16).toUpperCase();
-  }).join();
-}
-
 /// Like [String.split], but only splits on the first occurrence of the pattern.
 /// This will always return an array of two elements or fewer.
 ///
 ///     split1("foo,bar,baz", ","); //=> ["foo", "bar,baz"]
 ///     split1("foo", ","); //=> ["foo"]
 ///     split1("", ","); //=> []
 List<String> split1(String toSplit, String pattern) {
   if (toSplit.isEmpty) return <String>[];
 
   var index = toSplit.indexOf(pattern);
@@ skipping 152 matching lines @@
 /// The return values of all [Future]s are discarded. Any errors will cause the
 /// iteration to stop and will be piped through the return value.
 Future forEachFuture(Iterable input, Future fn(element)) {
   var iterator = input.iterator;
   Future nextElement(_) {
     if (!iterator.moveNext()) return new Future.value();
     return fn(iterator.current).then(nextElement);
   }
   return nextElement(null);
 }