Reapply "Rename mappedBy to map."

pkg/yaml/lib/yaml.dart

Index: pkg/yaml/lib/yaml.dart
diff --git a/pkg/yaml/lib/yaml.dart b/pkg/yaml/lib/yaml.dart
index ef0ac830b640035a5e72f7a8d980d7e5fdbe9e9a..e905e767d4ced5bf8e1674abf3943b9ac231e416 100644
--- a/pkg/yaml/lib/yaml.dart
+++ b/pkg/yaml/lib/yaml.dart
@@ -60,8 +60,8 @@ loadYaml(String yaml) {
 /// are YamlMaps. These have a few small behavioral differences from the default
 /// Map implementation; for details, see the YamlMap class.
 List loadYamlStream(String yaml) {
-  return new _Parser(yaml).l_yamlStream().mappedBy((doc) =>
-      new _Constructor(new _Composer(doc).compose()).construct())
+  return new _Parser(yaml).l_yamlStream()
+      .map((doc) => new _Constructor(new _Composer(doc).compose()).construct())
       .toList();
 }