Remove frog from the repository.

frog/tests/canvastest.dart

-// Copyright (c) 2011, 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.
-
-#import("dart:dom_deprecated");
-
-void main() {
-  var element = document.createElement('div');
-  element.innerHTML = "Hello from Dart!";
-  document.body.appendChild(element);
-
-  HTMLCanvasElement canvas = document.createElement('canvas');
-  canvas.setAttribute('width', '100');
-  canvas.setAttribute('height', '100');
-  document.body.appendChild(canvas);
-
-  var context = canvas.getContext('2d');
-  context.fillRect(10, 10, 20, 20);
-}