Don't call dinvoke on Object methods

lib/runtime/dart/convert.js

 var convert;
 (function(exports) {
   'use strict';
   let ASCII = new AsciiCodec();
   let _ASCII_MASK = 127;
   let _allowInvalid = Symbol('_allowInvalid');
   let _nameToEncoding = Symbol('_nameToEncoding');
   let Codec$ = dart.generic(function(S, T) {
     class Codec extends core.Object {
       Codec() {
@@ skipping 12 matching lines @@
       }
     }
     return Codec;
   });
   let Codec = Codec$();
   class Encoding extends Codec$(core.String, core.List$(core.int)) {
     Encoding() {
       super.Codec();
     }
     decodeStream(byteStream) {
-      return dart.as(byteStream.transform(dart.as(this.decoder, async.StreamTransformer$(core.List$(core.int), dynamic))).fold(new core.StringBuffer(), (buffer, string) => dart.dinvoke(buffer, 'write', string), buffer).then((buffer) => dart.dinvoke(buffer, 'toString')), async.Future$(core.String));
+      return dart.as(byteStream.transform(dart.as(this.decoder, async.StreamTransformer$(core.List$(core.int), dynamic))).fold(new core.StringBuffer(), (buffer, string) => dart.dinvoke(buffer, 'write', string), buffer).then((buffer) => buffer.toString()), async.Future$(core.String));
     }
     static getByName(name) {
       if (name == null)
         return null;
       name = name.toLowerCase();
       return Encoding[_nameToEncoding].get(name);
     }
   }
   dart.defineLazyProperties(Encoding, {
     get _nameToEncoding() {
@@ skipping 1481 matching lines @@
     writeAll(objects, separator) {
       if (separator === void 0)
         separator = "";
       if (this[_buffer].isNotEmpty)
         this[_flush]();
       let iterator = objects[core.$iterator];
       if (!dart.notNull(iterator.moveNext()))
         return;
       if (separator.isEmpty) {
         do {
-          this[_chunkedSink].add(dart.as(dart.dinvoke(iterator.current, 'toString'), core.String));
+          this[_chunkedSink].add(iterator.current.toString());
         } while (iterator.moveNext());
       } else {
-        this[_chunkedSink].add(dart.as(dart.dinvoke(iterator.current, 'toString'), core.String));
+        this[_chunkedSink].add(iterator.current.toString());
         while (iterator.moveNext()) {
           this.write(separator);
-          this[_chunkedSink].add(dart.as(dart.dinvoke(iterator.current, 'toString'), core.String));
+          this[_chunkedSink].add(iterator.current.toString());
         }
       }
     }
     [_flush]() {
       let accumulated = this[_buffer].toString();
       this[_buffer].clear();
       this[_chunkedSink].add(accumulated);
     }
   }
   _StringConversionSinkAsStringSinkAdapter[dart.implements] = () => [ClosableStringSink];
@@ skipping 817 matching lines @@
   exports.LineSplitter = LineSplitter;
   exports.StringConversionSink = StringConversionSink;
   exports.ClosableStringSink = ClosableStringSink;
   exports.UNICODE_REPLACEMENT_CHARACTER_RUNE = UNICODE_REPLACEMENT_CHARACTER_RUNE;
   exports.UNICODE_BOM_CHARACTER_RUNE = UNICODE_BOM_CHARACTER_RUNE;
   exports.UTF8 = UTF8;
   exports.Utf8Codec = Utf8Codec;
   exports.Utf8Encoder = Utf8Encoder;
   exports.Utf8Decoder = Utf8Decoder;
 })(convert || (convert = {}));