Fix so that logic to enable private user define @JS classes does not impact codegen for dart:html n…

sdk/lib/js/dartium/js_dartium.dart

 // Copyright (c) 2013, 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.
 
 /**
  * Support for interoperating with JavaScript.
  *
  * This library provides access to JavaScript objects from Dart, allowing
  * Dart code to get and set properties, and call methods of JavaScript objects
  * and invoke JavaScript functions. The library takes care of converting
@@ skipping 624 matching lines @@
           _isExternal(declaration)) {
         addMemberHelper(declaration, jsLibraryName, sb);
       }
     } else if (declaration is mirrors.ClassMirror) {
       mirrors.ClassMirror clazz = declaration;
       var isDom = dartLibrary ? hasDomName(clazz) : false;
       var isJsInterop = _hasJsName(clazz);
       if (isDom || isJsInterop) {
         // TODO(jacobr): verify class implements JavaScriptObject.
         var className = mirrors.MirrorSystem.getName(clazz.simpleName);
-        bool isPrivate = className.startsWith('_');
+        bool isPrivateUserDefinedClass =
+            className.startsWith('_') && !dartLibrary;
         var classNameImpl = '${className}Impl';
         var sbPatch = new StringBuffer();
         if (isJsInterop) {
           String jsClassName = _getJsMemberName(clazz);
 
           jsInterfaceTypes.add(clazz);
           clazz.declarations.forEach((name, declaration) {
             if (declaration is! mirrors.MethodMirror ||
                 !_isExternal(declaration)) return;
             if (declaration.isFactoryConstructor && _isAnonymousClass(clazz)) {
@@ skipping 52 matching lines @@
                       : jsClassName,
                   sbPatch,
                   isStatic: true);
             }
           });
         }
         if (isDom) {
           sbPatch.write(
               "  static Type get instanceRuntimeType => ${classNameImpl};\n");
         }
-        if (isPrivate) {
+        if (isPrivateUserDefinedClass) {

[terry, 2016/08/04 13:50:33]

I'm assuming this should not happen?  Are there class names in dart: libraries
with a _className that's a DOM class?

[terry, 2016/08/04 13:58:21]

Looks like there are classes in dart: with underscore that are DomName so I
suspect we'll need to regen the patch files for dartium?

           sb.write("""
 class ${escapePrivateClassPrefix}${className} implements $className {}
 """);
         }
 
         if (sbPatch.isNotEmpty) {
           var typeVariablesClause = '';
           if (!clazz.typeVariables.isEmpty) {
             typeVariablesClause =
                 '<${clazz.typeVariables.map((m) => mirrors.MirrorSystem.getName(m.simpleName)).join(',')}>';
@@ skipping 74 matching lines @@
 
   var implements = <String>[];
   var implementsArray = <String>[];
   var implementsDom = <String>[];
   var listMirror = mirrors.reflectType(List);
   var functionMirror = mirrors.reflectType(Function);
   var jsObjectMirror = mirrors.reflectType(JSObject);
 
   for (var typeMirror in jsInterfaceTypes) {
     mirrors.LibraryMirror libraryMirror = typeMirror.owner;
+    var location = libraryMirror.location;
+    var dartLibrary = location != null && location.sourceUri.scheme == 'dart';
+
     var prefixName;
     if (libraryPrefixes.containsKey(libraryMirror)) {
       prefixName = libraryPrefixes[libraryMirror];
     } else {
       var basePrefixName =
           mirrors.MirrorSystem.getName(libraryMirror.simpleName);
       basePrefixName = basePrefixName.replaceAll('.', '_');
       if (basePrefixName.isEmpty) basePrefixName = "lib";
       prefixName = basePrefixName;
       var i = 1;
       while (prefixNames.contains(prefixName)) {
         prefixName = '$basePrefixName$i';
         i++;
       }
       prefixNames.add(prefixName);
       libraryPrefixes[libraryMirror] = prefixName;
     }
     var isArray = typeMirror.isSubtypeOf(listMirror);
     var isFunction = typeMirror.isSubtypeOf(functionMirror);
     var isJSObject = typeMirror.isSubtypeOf(jsObjectMirror);
     var className = mirrors.MirrorSystem.getName(typeMirror.simpleName);
-    var isPrivate = className.startsWith('_');
-    if (isPrivate) className = '${escapePrivateClassPrefix}${className}';
+    var isPrivateUserDefinedClass = className.startsWith('_') && !dartLibrary;
+    if (isPrivateUserDefinedClass)
+      className = '${escapePrivateClassPrefix}${className}';
     var fullName = '${prefixName}.${className}';
     (isArray ? implementsArray : implements).add(fullName);
     if (!isArray && !isFunction && !isJSObject) {
       // For DOM classes we need to be a bit more conservative at tagging them
       // as implementing JS inteorp classes risks strange unintended
       // consequences as unrleated code may have instanceof checks.  Checking
       // for isJSObject ensures we do not accidentally pull in existing
       // dart:html classes as they all have JSObject as a base class.
       // Note that methods from these classes can still be called on a
       // dart:html instance but checked mode type checks will fail. This is
@@ skipping 843 matching lines @@
   } else {
     var ret = _interopCaptureThisExpando[f];
     if (ret == null) {
       // TODO(jacobr): we could optimize this.
       ret = JSFunction._createWithThis(f);
       _interopCaptureThisExpando[f] = ret;
     }
     return ret;
   }
 }