Added a positional Component.fromArgs() constructor

sky/framework/fn.dart

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 library fn;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:sky' as sky;
 import 'reflect.dart' as reflect;
@@ skipping 580 matching lines @@
   final int _order;
   static int _currentOrder = 0;
   bool _stateful;
   static Component _currentlyBuilding;
 
   Component({ Object key, bool stateful })
       : _stateful = stateful != null ? stateful : false,
         _order = _currentOrder + 1,
         super(key:key);
 
+  Component.fromArgs(Object key, bool stateful)
+      : this(key: key, stateful: stateful);
+
   void didMount() {}
   void didUnmount() {}
 
   // TODO(rafaelw): It seems wrong to expose DOM at all. This is presently
   // needed to get sizing info.
   sky.Node getRoot() => _root;
 
   void _remove() {
     assert(_built != null);
     assert(_root != null);
@@ skipping 96 matching lines @@
 
       _sync(null, _host, null);
       assert(_root is sky.Node);
 
       sw.stop();
       if (_shouldLogRenderDuration)
         print("Initial build: ${sw.elapsedMicroseconds} microseconds");
     });
   }
 }