Migrate dom tests to dart:html.

tests/dom/canvas_using_html_test.dart

 #library('CanvasUsingHtmlTest');
 #import('../../lib/unittest/unittest.dart');
-#import('../../lib/unittest/dom_config.dart');
+#import('../../lib/unittest/html_config.dart');
 #import('dart:html', prefix: 'html');
-#import('dart:dom');
+#import('dart:html');
 
 // Version of Canvas test that implicitly uses dart:html library via unittests.
 
 main() {
-  HTMLCanvasElement canvas;
+  CanvasElement canvas;
   CanvasRenderingContext2D context;
 
-  canvas = document.createElement('canvas');
-  canvas.setAttribute('width', '100');
-  canvas.setAttribute('height', '100');
-  document.body.appendChild(canvas);
+  canvas = new Element.tag('canvas');
+  canvas.attributes['width'] = '100';

[Anton Muhin, 2012/04/27 12:06:34]

ditto

+  canvas.attributes['height'] = '100';
+  document.body.nodes.add(canvas);
   context = canvas.getContext('2d');
 
-  useDomConfiguration();
+  useHtmlConfiguration();
   test('FillStyle', () {
     context.fillStyle = "red";
     context.fillRect(10, 10, 20, 20);
 
     // TODO(vsm): Verify the result once we have the ability to read pixels.
   });
   test('SetFillColor', () {
     // With floats.
     context.setFillColor(10, 10, 10, 10);
     context.fillRect(10, 10, 20, 20);
@@ skipping 18 matching lines @@
     ImageData image = context.createImageData(canvas.width,
                                               canvas.height);
     Uint8ClampedArray bytes = image.data;
 
     // FIXME: uncomment when numeric index getters are supported.
     //var byte = bytes[0];
 
     Expect.equals(40000, bytes.length);
   });
 }