dart2js: Remove obsolete comment and code.

pkg/compiler/lib/src/js_emitter/native_emitter.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart2js.js_emitter;
 
 class NativeEmitter {
 
   final Map<Element, ClassBuilder> cachedBuilders;
 
@@ skipping 264 matching lines @@
   }
 
   ClassBuilder generateNativeClass(ClassElement classElement) {
     // TODO(sra): Issue #13731- this is commented out as part of custom element
     // constructor work.
     //assert(!classElement.hasBackendMembers);
     hasNativeClasses = true;
 
     ClassElement superclass = classElement.superclass;
     assert(superclass != null);
-    // Fix superclass.  TODO(sra): make native classes inherit from Interceptor.
     assert(superclass != compiler.objectClass);
-    if (superclass == compiler.objectClass) {
-      superclass = backend.jsInterceptorClass;
-    }
 
     String superName = backend.namer.getNameOfClass(superclass);
 
     ClassBuilder builder;
     if (compiler.hasIncrementalSupport) {
       builder = cachedBuilders[classElement];
       if (builder != null) return builder;
       builder = new ClassBuilder(classElement, backend.namer);
       cachedBuilders[classElement] = builder;
     } else {
@@ skipping 170 matching lines @@
         targetOutput.add(';');
       }
       targetOutput.addBuffer(jsAst.prettyPrint(
           new jsAst.ExpressionStatement(init), compiler));
       targetOutput.add('\n');
     }
 
     targetOutput.add('\n');
   }
 }