Revert "Steps towards making the convert library strong-mode compliant."

sdk/lib/convert/base64.dart

Index: sdk/lib/convert/base64.dart
diff --git a/sdk/lib/convert/base64.dart b/sdk/lib/convert/base64.dart
index ff3a43959e1074818c120cbaa56c13f604357ca7..c6cac6ed76cf42f1d7641cebbef604f7de72eb13 100644
--- a/sdk/lib/convert/base64.dart
+++ b/sdk/lib/convert/base64.dart
@@ -70,8 +70,7 @@ class Base64Codec extends Codec<List<int>, String> {
  *
  * The results are ASCII strings using a restricted alphabet.
  */
-class Base64Encoder extends
-    ChunkedConverter<List<int>, String, List<int>, String> {
+class Base64Encoder extends Converter<List<int>, String> {
   final bool _urlSafe;
 
   const Base64Encoder() : _urlSafe = false;
@@ -90,6 +89,14 @@ class Base64Encoder extends
     }
     return new _AsciiBase64EncoderSink(sink, _urlSafe);
   }
+
+  Stream<String> bind(Stream<List<int>> stream) {
+    return new Stream<String>.eventTransformed(
+        stream,
+        (EventSink sink) =>
+            new _ConverterStreamEventSink<List<int>, String>(
+                this, sink));
+  }
 }
 
 /**
@@ -341,9 +348,7 @@ class _Utf8Base64EncoderSink extends _Base64EncoderSink {
  *
  * The encoding is required to be properly padded.
  */
-class Base64Decoder extends
-    ChunkedConverter<String, List<int>, String, List<int>> {
-
+class Base64Decoder extends Converter<String, List<int>> {
   const Base64Decoder();
 
   List<int> convert(String input, [int start = 0, int end]) {