Revert "Constructors for IDBKeyRange"

lib/dom/src/frog_IDBKeyRangeFactoryProvider.dart

-// 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 _IDBKeyRangeFactoryProvider {
-
-  factory IDBKeyRange.only(/*IDBKey*/ value) =>
-      _only(_class(), _translateKey(value));
-
-  factory IDBKeyRange.lowerBound(/*IDBKey*/ bound, [bool open = false]) =>
-      _lowerBound(_class(), _translateKey(bound), open);
-
-  factory IDBKeyRange.upperBound(/*IDBKey*/ bound, [bool open = false]) =>
-      _upperBound(_class(), _translateKey(bound), open);
-
-  factory IDBKeyRange.bound(/*IDBKey*/ lower, /*IDBKey*/ upper,
-                            [bool lowerOpen = false, bool upperOpen = false]) =>
-      _bound(_class(), _translateKey(lower), _translateKey(upper),
-             lowerOpen, upperOpen);
-
-  static var _cachedClass;
-
-  static _class() {
-    if (_cachedClass != null) return _cachedClass;
-    return _cachedClass = _uncachedClass();
-  }
-
-  static _uncachedClass() native '''
-      return window.webkitIDBKeyRange || window.mozIDBKeyRange ||
-             window.msIDBKeyRange || window.IDBKeyRange;
-  ''';
-
-  static _translateKey(idbkey) => idbkey;  // TODO: fixme.
-
-  static _IDBKeyRangeJs _only(cls, value) native
-      '''return cls.only(value);''';
-
-  static _IDBKeyRangeJs _lowerBound(cls, bound, open) native
-      '''return cls.lowerBound(bound, open);''';
-
-  static _IDBKeyRangeJs _upperBound(cls, bound, open) native
-      '''return cls.upperBound(bound, open);''';
-
-  static _IDBKeyRangeJs _bound(cls, lower, upper, lowerOpen, upperOpen) native
-      '''return cls.bound(lower, upper, lowerOpen, upperOpen);''';
-
-}