CanvasRenderingContext2D.fillText now works correctly with null maxWidth.

tests/html/canvasrenderingcontext2d_test.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 canvas_rendering_context_2d_test; import '../../pkg/unittest/lib/unittest.dart';
 import '../../pkg/unittest/lib/html_individual_config.dart';
 import 'dart:html';
 import 'dart:math';
 
 // Some rounding errors in the browsers.
@@ skipping 656 matching lines @@
       var other = context.createImageDataFromImageData(imageData);
       expect(other.width, 15);
       expect(other.height, 15);
     });
 
     test('createPattern', () {
       var pattern = context.createPattern(new CanvasElement(), '');
       //var pattern2 = context.createPatternFromImage(new ImageElement(), '');
     });
   });
+
+  group('fillText', () {
+    setUp(setupFunc);
+    tearDown(tearDownFunc);
+
+    test('with maxWidth defined', () {
+      context.font = '40pt Garamond';
+      context.fillStyle = 'blue';
+
+      // Draw a blue box that's at most 20 pixels wide.
+      context.fillText('█', 50, 50, 20);
+
+      checkPixel(readPixel(50, 50), [0, 0, 255, 255]);
+      checkPixel(readPixel(60, 50), [0, 0, 255, 255]);
+
+      // The box does not draw after 20 pixels.
+      expectPixelUnfilled(40, 50);
+      expectPixelUnfilled(71, 50);
+      expectPixelUnfilled(90, 50);
+      expectPixelFilled(50, 50);
+      expectPixelFilled(60, 50);
+    });
+
+    test('with maxWidth null', () {
+      context.font = '40pt Garamond';
+      context.fillStyle = 'blue';
+
+      // Draw a blue box with null maxWidth.
+      context.fillText('█', 50, 50, null);
+
+      checkPixel(readPixel(50, 50), [0, 0, 255, 255]);
+      checkPixel(readPixel(60, 50), [0, 0, 255, 255]);
+
+      expectPixelUnfilled(40, 50);
+      expectPixelUnfilled(90, 50);
+      expectPixelFilled(50, 50);
+      expectPixelFilled(60, 50);
+      expectPixelFilled(70, 50);
+    });
+  });
 }