Reapply "Rename mappedBy to map."

sdk/lib/async/stream.dart

Index: sdk/lib/async/stream.dart
diff --git a/sdk/lib/async/stream.dart b/sdk/lib/async/stream.dart
index 3911b674b26759c78a6a9dfac99c488a4f0dffb8..afdeaf3fa84f450b0f57081dda980874b5490c81 100644
--- a/sdk/lib/async/stream.dart
+++ b/sdk/lib/async/stream.dart
@@ -129,11 +129,18 @@ abstract class Stream<T> {
    * Create a new stream that converts each element of this stream
    * to a new value using the [convert] function.
    */
-  Stream mappedBy(convert(T event)) {
+  Stream map(convert(T event)) {
     return new _MapStream<T, dynamic>(this, convert);
   }
 
   /**
+   * Deprecated alias for [map].
+   *
+   * @deprecated
+   */
+  Stream mappedBy(f(T element)) => map(f);
+
+  /**
    * Create a wrapper Stream that intercepts some errors from this stream.
    *
    * If this stream sends an error that matches [test], then it is intercepted