implement user-defined nSM, Object members on functions

tool/input_sdk/private/ddc_runtime/classes.dart

Index: tool/input_sdk/private/ddc_runtime/classes.dart
diff --git a/tool/input_sdk/private/ddc_runtime/classes.dart b/tool/input_sdk/private/ddc_runtime/classes.dart
index d8b06e6cd72ca795d814f50db976806ffe237678..20e3db4416dd88a755014face55e496f3a5e9c6a 100644
--- a/tool/input_sdk/private/ddc_runtime/classes.dart
+++ b/tool/input_sdk/private/ddc_runtime/classes.dart
@@ -335,12 +335,9 @@ void _installPropertiesForObject(jsProto, coreObjProto) {
   return;
 }
 
-
-///
 /// Copy symbols from the prototype of the source to destination.
 /// These are the only properties safe to copy onto an existing public
 /// JavaScript class.
-///
 registerExtension(jsType, dartExtType) => JS('', '''(() => {
   // TODO(vsm): Not all registered js types are real.
   if (!jsType) return;
@@ -402,18 +399,6 @@ defineExtensionMembers(type, methodNames) => JS('', '''(() => {
   });
 })()''');
 
-canonicalMember(obj, name) => JS('', '''(() => {
-  // Private names are symbols and are already canonical.
-  if (typeof name === 'symbol') return name;
-
-  if ($obj != null && $obj[$_extensionType]) return $dartx[$name];
-  // Check for certain names that we can't use in JS
-  if ($name == 'constructor' || $name == 'prototype') {
-    $name = '+' + $name;
-  }
-  return $name;
-})()''');
-
 /// Sets the type of `obj` to be `type`
 setType(obj, type) {
   JS('', '#.__proto__ = #.prototype', obj, type);