Rename context2d to context2D.

samples/spirodraw/web/colorpicker.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 spirodraw;
 
 typedef void PickerListener(String selectedColor);
 
 class ColorPicker {
   static const hexValues = const ['00', '33', '66', '99', 'CC', 'FF'];
   static const COLS = 18;
   // Block height, width, padding
   static const BH = 10;
   static const BW = 10;
   static const BP = 1;
   final List<PickerListener> _listeners;
   CanvasElement canvasElement;
   String _selectedColor = 'red';
   final height = 160;
   final width = 180;
   CanvasRenderingContext2D ctx;
 
   ColorPicker(this.canvasElement) :
     _listeners = []
   {
-    ctx = canvasElement.context2d;
+    ctx = canvasElement.context2D;
     drawPalette();
     addHandlers();
     showSelected();
   }
 
   String get selectedColor => _selectedColor;
 
   void set selectedColor(String color) {
     _selectedColor = color;
 
@@ skipping 73 matching lines @@
     int i = value.floor().toInt();
 
     int r = (i ~/ 36) % 6;
     int g = (i % 36) ~/ 6;
     int b = i % 6;
 
     return '#${hexValues[r]}${hexValues[g]}${hexValues[b]}';
   }
 
 }