Changed @domName annotation in comment to full fledge @DomName annotation.

tools/dom/templates/html/impl/impl_CanvasRenderingContext2D.darttemplate

 // 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 html;
-
-/// @domName $DOMNAME
+$ANNOTATIONS
 class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
 $!MEMBERS
 
   /**
    * Sets the color used inside shapes.
    * [r], [g], [b] are 0-255, [a] is 0-1.
    */
   void setFillColorRgb(int r, int g, int b, [num a = 1]) {
     this.fillStyle = 'rgba($r, $g, $b, $a)';
   }
@@ skipping 19 matching lines @@
   /**
    * Sets the color used for stroking shapes.
    * [h] is in degrees, 0-360.
    * [s], [l] are in percent, 0-100.
    * [a] is 0-1.
    */
   void setStrokeColorHsl(int h, num s, num l, [num a = 1]) {
     this.strokeStyle = 'hsla($h, $s%, $l%, $a)';
   }
 }