Reapply lineDash with polyfill.

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 $LIBRARYNAME;
 
 $(ANNOTATIONS)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
 $!MEMBERS
 
   /**
@@ skipping 235 matching lines @@
 $else
   void drawImageScaledFromSource(CanvasImageSource source,
       num sourceX, num sourceY, num sourceWidth, num sourceHeight,
       num destX, num destY, num destWidth, num destHeight) {
     _drawImage(source, sourceX, sourceY, sourceWidth, sourceHeight,
         destX, destY, destWidth, destHeight);
   }
 $endif
 
 $if DART2JS
+  @SupportedBrowser(SupportedBrowser.CHROME)
+  @SupportedBrowser(SupportedBrowser.SAFARI)
+  @SupportedBrowser(SupportedBrowser.IE, '11')
+  @Unstable()
   @DomName('CanvasRenderingContext2D.lineDashOffset')
+  // TODO(14316): Firefox has this functionality with mozDashOffset, but it
+  // needs to be polyfilled.
   num get lineDashOffset => JS('num',
       '#.lineDashOffset || #.webkitLineDashOffset', this, this);
 
+  @SupportedBrowser(SupportedBrowser.CHROME)
+  @SupportedBrowser(SupportedBrowser.SAFARI)
+  @SupportedBrowser(SupportedBrowser.IE, '11')
+  @Unstable()
   @DomName('CanvasRenderingContext2D.lineDashOffset')
+  // TODO(14316): Firefox has this functionality with mozDashOffset, but it
+  // needs to be polyfilled.
   void set lineDashOffset(num value) => JS('void',
       'typeof #.lineDashOffset != "undefined" ? #.lineDashOffset = # : '
       '#.webkitLineDashOffset = #', this, this, value, this, value);
 $else
   // TODO(amouravski): Add Dartium native methods for drawImage once we figure
   // out how to not break native bindings.
 $endif
+
+  @SupportedBrowser(SupportedBrowser.CHROME)
+  @SupportedBrowser(SupportedBrowser.SAFARI)
+  @SupportedBrowser(SupportedBrowser.IE, '11')
+  @Unstable()
+  @DomName('CanvasRenderingContext2D.getLineDash')
+  List<num> getLineDash() {
+    // TODO(14316): Firefox has this functionality with mozDash, but it's a bit
+    // different.
+$if DART2JS
+    if (JS('bool', '!!#.getLineDash', this)) {
+      return JS('List<num>', '#.getLineDash()', this);
+    } else if (JS('bool', '!!#.webkitLineDash', this)) {
+      return JS('List<num>', '#.webkitLineDash', this);
+    } 
+$else
+    var result = _getLineDash();
+    if (result == null) {
+      result = [];
+    }
+    return result;
+$endif
+  }
+
+$if DART2JS
+  @SupportedBrowser(SupportedBrowser.CHROME)
+  @SupportedBrowser(SupportedBrowser.SAFARI)
+  @SupportedBrowser(SupportedBrowser.IE, '11')
+  @Unstable()
+  @DomName('CanvasRenderingContext2D.setLineDash')
+  void setLineDash(List<num> dash) {
+    // TODO(14316): Firefox has this functionality with mozDash, but it's a bit
+    // different.
+    if (JS('bool', '!!#.setLineDash', this)) {
+      JS('void', '#.setLineDash(#)', this, dash);
+    } else if (JS('bool', '!!#.webkitLineDash', this)) {
+      JS('void', '#.webkitLineDash = #', this, dash);
+    }
+  }
+$endif
+
 $if DART2JS
 
   /**
    * Draws text to the canvas.
    *
    * The text is drawn starting at coordinates ([x], [y]).
    * If [maxWidth] is provided and the [text] is computed to be wider than
    * [maxWidth], then the drawn text is scaled down horizontally to fit.
    *
    * The text uses the current [CanvasRenderingContext2D.font] property for font
    * options, such as typeface and size, and the current
    * [CanvasRenderingContext2D.fillStyle] for style options such as color.
    * The current [CanvasRenderingContext2D.textAlign] and
    * [CanvasRenderingContext2D.textBaseLine] properties are also applied to the
    * drawn text.
    */
   @DomName('CanvasRenderingContext2D.fillText')
   void fillText(String text, num x, num y, [num maxWidth]) {
     if (maxWidth != null) {
       JS('void', '#.fillText(#, #, #, #)', this, text, x, y, maxWidth);
     } else {
       JS('void', '#.fillText(#, #, #)', this, text, x, y);
     }
   }
 $endif
 }