Make the ClassMirrors created through reflectClass() find their owners (libraries) lazily.

runtime/lib/mirrors_impl.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.
 
 // VM-specific implementation of the dart:mirrors library.
 
 // These values are allowed to be passed directly over the wire.
 bool _isSimpleValue(var value) {
   return (value == null || value is num || value is String || value is bool);
 }
@@ skipping 404 matching lines @@
   Symbol _qualifiedName = null;
   Symbol get qualifiedName {
     if (_qualifiedName == null) {
       _qualifiedName = _computeQualifiedName(owner, simpleName);
     }
     return _qualifiedName;
   }
 
   var _owner;
   DeclarationMirror get owner {
-    if (_owner != null && _owner is! Mirror) {
+    if (_owner == null) {
+      _owner = _library(_reflectee);
+    }
+    if (_owner is! Mirror) {
       _owner = _owner.resolve(mirrors);
     }
     return _owner;
   }
 
   bool get isPrivate => _n(simpleName).startsWith('_');
 
   final bool isTopLevel = true;
 
   SourceLocation get location {
@@ skipping 130 matching lines @@
 
   List<InstanceMirror> get metadata {
     // get the metadata objects, convert them into InstanceMirrors using
     // reflect() and then make them into a Dart list
     return _metadata(_reflectee).map(reflect).toList();
   }
 
   static _name(reflectee)
       native "ClassMirror_name";
 
+  static _library(reflectee)
+      native "ClassMirror_library";
+
   _invoke(reflectee, memberName, positionalArguments)
       native 'ClassMirror_invoke';
 
   _invokeGetter(reflectee, getterName)
       native 'ClassMirror_invokeGetter';
 
   _invokeSetter(reflectee, setterName, value)
       native 'ClassMirror_invokeSetter';
 
   static _invokeConstructor(reflectee, constructorName, positionalArguments)
@@ skipping 531 matching lines @@
   }
 
   // Creates a new local ClassMirror.
   static ClassMirror makeLocalClassMirror(Type key)
       native "Mirrors_makeLocalClassMirror";
 
   static ClassMirror reflectClass(Type key) {
     return makeLocalClassMirror(key);
   }
 }