keep mixin and interface implementation info at runtime

lib/runtime/dart/convert.js

Index: lib/runtime/dart/convert.js
diff --git a/lib/runtime/dart/convert.js b/lib/runtime/dart/convert.js
index 099f6d1fb3528c0ee80ac53ff79f5234c0cdb4be..a61f5b3005f75d6d9a473639c0bb9f9cc970c2b2 100644
--- a/lib/runtime/dart/convert.js
+++ b/lib/runtime/dart/convert.js
@@ -86,6 +86,7 @@ var convert;
         return new async.Stream.eventTransformed(source, ((sink) => new _ConverterStreamEventSink(this, sink)).bind(this));
       }
     }
+    Converter[dart.implements] = [async.StreamTransformer];
     return Converter;
   });
   let Converter = Converter$(dart.dynamic, dart.dynamic);
@@ -141,6 +142,7 @@ var convert;
       return new _StringConversionSinkAsStringSinkAdapter(this);
     }
   }
+  StringConversionSinkMixin[dart.implements] = [StringConversionSink];
   class StringConversionSinkBase extends StringConversionSinkMixin {
   }
   class _UnicodeSubsetEncoderSink extends StringConversionSinkBase {
@@ -236,6 +238,7 @@ var convert;
         return new _SimpleCallbackSink(callback);
       }
     }
+    ChunkedConversionSink[dart.implements] = [core.Sink$(T)];
     dart.defineNamedConstructor(ChunkedConversionSink, 'withCallback');
     return ChunkedConversionSink;
   });
@@ -399,6 +402,7 @@ var convert;
         return this[_sink].close();
       }
     }
+    _EventSinkAdapter[dart.implements] = [ChunkedConversionSink$(T)];
     return _EventSinkAdapter;
   });
   let _EventSinkAdapter = _EventSinkAdapter$(dart.dynamic);
@@ -422,6 +426,7 @@ var convert;
         return this[_chunkedSink].close();
       }
     }
+    _ConverterStreamEventSink[dart.implements] = [async.EventSink$(S)];
     return _ConverterStreamEventSink;
   });
   let _ConverterStreamEventSink = _ConverterStreamEventSink$(dart.dynamic, dart.dynamic);
@@ -1080,6 +1085,7 @@ var convert;
       }
     }
   }
+  _JsonPrettyPrintMixin[dart.implements] = [_JsonStringifier];
   class _JsonStringStringifier extends _JsonStringifier {
     _JsonStringStringifier(sink$, _toEncodable) {
       this[_sink] = sink$;
@@ -1478,6 +1484,7 @@ var convert;
       return this[_sink].writeAll(objects, separator);
     }
   }
+  _ClosableStringSink[dart.implements] = [ClosableStringSink];
   let _flush = Symbol('_flush');
   let _MIN_STRING_SIZE = Symbol('_MIN_STRING_SIZE');
   class _StringConversionSinkAsStringSinkAdapter extends core.Object {
@@ -1534,6 +1541,7 @@ var convert;
       this[_chunkedSink].add(accumulated);
     }
   }
+  _StringConversionSinkAsStringSinkAdapter[dart.implements] = [ClosableStringSink];
   _StringConversionSinkAsStringSinkAdapter._MIN_STRING_SIZE = 16;
   let _stringSink = Symbol('_stringSink');
   class _StringSinkConversionSink extends StringConversionSinkBase {
@@ -2285,6 +2293,7 @@ var convert;
       return Object.create(null);
     }
   }
+  _JsonMap[dart.implements] = [collection.LinkedHashMap];
   let _parent = Symbol('_parent');
   class _JsonMapKeyIterable extends _internal.ListIterable {
     _JsonMapKeyIterable(parent) {