Revert "Revert "Constructors for IDBKeyRange""

lib/dom/src/frog_IDBKeyRangeFactoryProvider.dart

Index: lib/dom/src/frog_IDBKeyRangeFactoryProvider.dart
diff --git a/lib/dom/src/frog_IDBKeyRangeFactoryProvider.dart b/lib/dom/src/frog_IDBKeyRangeFactoryProvider.dart
new file mode 100644
index 0000000000000000000000000000000000000000..dfe16304c711f13f050b8aa7e3405b64475d74e8
--- /dev/null
+++ b/lib/dom/src/frog_IDBKeyRangeFactoryProvider.dart
@@ -0,0 +1,47 @@
+// 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);''';
+
+}