Modified unittest to use new argument syntax.

tests/html/canvas_pixel_array_type_alias_test.dart

 #library('CanvasTest');
 #import('../../pkg/unittest/unittest.dart');
 #import('../../pkg/unittest/html_config.dart');
 #import('dart:html');
 
 // We have aliased the legacy type CanvasPixelArray with the new type
 // Uint8ClampedArray by mapping the CanvasPixelArray type tag to
 // Uint8ClampedArray.  It is not a perfect match since CanvasPixelArray is
 // missing the ArrayBufferView members.  These should appear to be null.
 
@@ skipping 13 matching lines @@
   context = canvas.getContext('2d');
 
   useHtmlConfiguration();
 
   test('CreateImageData', () {
     ImageData image = context.createImageData(canvas.width,
                                               canvas.height);
     Uint8ClampedArray data = image.data;
     // It is legal for the dart2js compiler to believe the type of the native
     // ImageData.data and elides the check, so check the type explicitly:
-    expect(confuseType(data) is Uint8ClampedArray, isTrue, 'canvas array type');
+    expect(confuseType(data) is Uint8ClampedArray, isTrue,
+        reason: 'canvas array type');
 
     expect(data, hasLength(40000));
     checkPixel(data, 0, [0, 0, 0, 0]);
     checkPixel(data, width * height - 1, [0, 0, 0, 0]);
 
     data[100] = 200;
     expect(data[100], equals(200));
   });
 }
 
 void checkPixel(Uint8ClampedArray data, int offset, List<int> rgba)
 {
   offset *= 4;
   for (var i = 0; i < 4; ++i) {
-    Expect.equals(rgba[i], data[offset + i]);
+    expect(rgba[i], equals(data[offset + i]));
   }
 }