Some HTML API cleanup

lib/html/frog/html_frog.dart

Index: lib/html/frog/html_frog.dart
diff --git a/lib/html/frog/html_frog.dart b/lib/html/frog/html_frog.dart
index 4bff43aa16ab4f388825685370483ca7bde6a6d5..e2e42d5610e6fb786a6a53422ee6ffa78ed22f18 100644
--- a/lib/html/frog/html_frog.dart
+++ b/lib/html/frog/html_frog.dart
@@ -19,6 +19,9 @@ Document get document() native "return document;";
 
 _DocumentImpl get _document() native "return document;";
 
+Element query(String selector) => _document.query(selector);
+ElementList queryAll(String selector) => _document.queryAll(selector);
+
 // Workaround for tags like <cite> that lack their own Element subclass --
 // Dart issue 1990.
 class _HTMLElementImpl extends _ElementImpl native "*HTMLElement" {
@@ -3778,6 +3781,9 @@ class _CSSValueListImpl extends _CSSValueImpl implements CSSValueList native "*C
 
   _CSSValueImpl item(int index) native;
 }
+// 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.
 
 class _CanvasElementImpl extends _ElementImpl implements CanvasElement native "*HTMLCanvasElement" {
 
@@ -3788,6 +3794,9 @@ class _CanvasElementImpl extends _ElementImpl implements CanvasElement native "*
   Object getContext(String contextId) native;
 
   String toDataURL(String type) native;
+
+
+  CanvasRenderingContext2D get context2d() => getContext('2d');
 }
 
 class _CanvasGradientImpl implements CanvasGradient native "*CanvasGradient" {