Rename context2d to context2D.

samples/sunflower/web/sunflower.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.
 
 library sunflower;
 
 import 'dart:html';
 import 'dart:math';
 
 const String ORANGE = "orange";
 const int SEED_RADIUS = 2;
 const int SCALE_FACTOR = 4;
 const num TAU = PI * 2;
 const int MAX_D = 300;
 const num centerX = MAX_D / 2;
 const num centerY = centerX;
 
 final InputElement slider = query("#slider");
 final Element notes = query("#notes");
 final num PHI = (sqrt(5) + 1) / 2;
 int seeds = 0;
 final CanvasRenderingContext2D context =
-  (query("#canvas") as CanvasElement).context2d;
+  (query("#canvas") as CanvasElement).context2D;
 
 void main() {
   slider.onChange.listen((e) => draw());
   draw();
 }
 
 /// Draw the complete figure for the current number of seeds.
 void draw() {
   seeds = int.parse(slider.value);
   context.clearRect(0, 0, MAX_D, MAX_D);
   for (var i = 0; i < seeds; i++) {
     final num theta = i * TAU / PHI;
     final num r = sqrt(i) * SCALE_FACTOR;
     drawSeed(centerX + r * cos(theta), centerY - r * sin(theta));
   }
   notes.text = "${seeds} seeds";
 }
 
 /// Draw a small circle representing a seed centered at (x,y).
 void drawSeed(num x, num y) {
   context..beginPath()
          ..lineWidth = 2
          ..fillStyle = ORANGE
          ..strokeStyle = ORANGE
          ..arc(x, y, SEED_RADIUS, 0, TAU, false)
          ..fill()
          ..closePath()
          ..stroke();
 }