Change void typed setters in html_dart2js not to return a value.

sdk/lib/_blink/dartium/_blink_dartium.dart

 /**
  * This library provides entry points to the native Blink code which backs
  * up the dart:html library.
  */
 library dart.dom._blink;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:html';
 import 'dart:_internal' hide Symbol, deprecated;
@@ skipping 2151 matching lines @@
   static $mkFileReader() {
     return $_create_1constructorCallback();
   }
 
   static $_create_1constructorCallback() native "FileReader_constructorCallback_RESOLVER_STRING_0_";
 
   static $error_Getter(mthis) native "FileReader_error_Getter";
 
   static $readyState_Getter(mthis) native "FileReader_readyState_Getter";
 
-  static $result_Getter(mthis) native "FileReader_result_Getter";
-
   static $abort_Callback(mthis) native "FileReader_abort_Callback_RESOLVER_STRING_0_";
 
   static $readAsArrayBuffer_Callback(mthis, blob) native "FileReader_readAsArrayBuffer_Callback_RESOLVER_STRING_1_Blob";
 
   static $readAsDataURL_Callback(mthis, blob) native "FileReader_readAsDataURL_Callback_RESOLVER_STRING_1_Blob";
 
   // Generated overload resolver
   static $readAsText(mthis, blob, encoding) {
     if (encoding != null) {
       $_readAsText_1_Callback(mthis, blob, encoding);
@@ skipping 5942 matching lines @@
 
   static $previousSibling_Callback(mthis) native "TreeWalker_previousSibling_Callback_RESOLVER_STRING_0_";
 }
 
 class BlinkURL {
   // Generated overload resolver
   static $createObjectUrl(blob_OR_source_OR_stream) {
     if ((blob_OR_source_OR_stream is Blob || blob_OR_source_OR_stream == null)) {
       return $_createObjectURL_1_Callback(blob_OR_source_OR_stream);
     }
-    if ((blob_OR_source_OR_stream is MediaSource || blob_OR_source_OR_stream == null)) {
+    if ((blob_OR_source_OR_stream is MediaStream || blob_OR_source_OR_stream == null)) {
       return $_createObjectURL_2_Callback(blob_OR_source_OR_stream);
     }
-    if ((blob_OR_source_OR_stream is MediaStream || blob_OR_source_OR_stream == null)) {
+    if ((blob_OR_source_OR_stream is MediaSource || blob_OR_source_OR_stream == null)) {
       return $_createObjectURL_3_Callback(blob_OR_source_OR_stream);
     }
     throw new ArgumentError("Incorrect number or type of arguments");
   }
 
   static $_createObjectURL_1_Callback(blob_OR_source_OR_stream) native "URL_createObjectURL_Callback_RESOLVER_STRING_1_Blob";
 
-  static $_createObjectURL_2_Callback(blob_OR_source_OR_stream) native "URL_createObjectURL_Callback_RESOLVER_STRING_1_MediaSource";
+  static $_createObjectURL_2_Callback(blob_OR_source_OR_stream) native "URL_createObjectURL_Callback_RESOLVER_STRING_1_MediaStream";
 
-  static $_createObjectURL_3_Callback(blob_OR_source_OR_stream) native "URL_createObjectURL_Callback_RESOLVER_STRING_1_MediaStream";
+  static $_createObjectURL_3_Callback(blob_OR_source_OR_stream) native "URL_createObjectURL_Callback_RESOLVER_STRING_1_MediaSource";
 
   static $createObjectUrlFromBlob_Callback(blob) native "URL_createObjectURL_Callback_RESOLVER_STRING_1_Blob";
 
   static $createObjectUrlFromSource_Callback(source) native "URL_createObjectURL_Callback_RESOLVER_STRING_1_MediaSource";
 
   static $createObjectUrlFromStream_Callback(stream) native "URL_createObjectURL_Callback_RESOLVER_STRING_1_MediaStream";
 
   static $revokeObjectURL_Callback(url) native "URL_revokeObjectURL_Callback_RESOLVER_STRING_1_DOMString";
 
   static $hash_Getter(mthis) native "URL_hash_Getter";
@@ skipping 1343 matching lines @@
   static containsKey(_DOMStringMap, key) native "DOMStringMap_containsKey_Callback";
 
   static item(_DOMStringMap, key) native "DOMStringMap_item_Callback";
 
   static setItem(_DOMStringMap, key, value) native "DOMStringMap_setItem_Callback";
 
   static remove(_DOMStringMap, key) native "DOMStringMap_remove_Callback";
 
   static get_keys(_DOMStringMap) native "DOMStringMap_getKeys_Callback";
 }