Fix CanvasPixelArray's operator[] for the wrapping js dom

client/dom/generated/src/wrapping/_CanvasPixelArrayWrappingImplementation.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.
 
 // WARNING: Do not edit - generated code.
 
 class _CanvasPixelArrayWrappingImplementation extends DOMWrapperBase implements CanvasPixelArray {
   _CanvasPixelArrayWrappingImplementation() : super() {}
 
   static create__CanvasPixelArrayWrappingImplementation() native {
     return new _CanvasPixelArrayWrappingImplementation();
   }
 
   int get length() { return _get_length(this); }
   static int _get_length(var _this) native;
 
-  int operator[](int index) {
-    return item(index);
-  }
+  int operator[](int index) { return _index(this, index); }
+  static int _index(var _this, int index) native;
 
   void operator[]=(int index, int value) {
-    throw new UnsupportedOperationException("Cannot assign element of immutable List.");
+    return _set_index(this, index, value);
   }
+  static _set_index(_this, index, value) native;
 
   void add(int value) {
     throw new UnsupportedOperationException("Cannot add to immutable List.");
   }
 
   void addLast(int value) {
     throw new UnsupportedOperationException("Cannot add to immutable List.");
   }
 
   void addAll(Collection<int> collection) {
@@ skipping 62 matching lines @@
   }
 
   bool isEmpty() {
     return length == 0;
   }
 
   Iterator<int> iterator() {
     return new _FixedSizeListIterator<int>(this);
   }
 
-  int item(int index) {
-    return _item(this, index);
-  }
-  static int _item(receiver, index) native;
-
   String get typeName() { return "CanvasPixelArray"; }
 }