Add IDBKeyRange to dart:html, port two indexeddb tests

lib/html/src/dartium_FactoryProviders.dart

Index: lib/html/src/dartium_FactoryProviders.dart
diff --git a/lib/html/src/dartium_FactoryProviders.dart b/lib/html/src/dartium_FactoryProviders.dart
index 049baf8aca36d381fb5ebf2d8b75fc3d8cf7e7fc..d098d9df0bc0dd7c228a5204447f9f9f897eb109 100644
--- a/lib/html/src/dartium_FactoryProviders.dart
+++ b/lib/html/src/dartium_FactoryProviders.dart
@@ -6,6 +6,23 @@ class _AudioContextFactoryProvider {
   factory AudioContext() => _wrap(new dom.AudioContext());
 }
 
+class _IDBKeyRangeFactoryProvider {
+
+  factory IDBKeyRange.only(/*IDBKey*/ value) =>
+      _wrap(new dom.IDBKeyRange.only(_unwrap(value)));
+
+  factory IDBKeyRange.lowerBound(/*IDBKey*/ bound, [bool open = false]) =>
+      _wrap(new dom.IDBKeyRange.lowerBound(_unwrap(bound), open));
+
+  factory IDBKeyRange.upperBound(/*IDBKey*/ bound, [bool open = false]) =>
+      _wrap(new dom.IDBKeyRange.upperBound(_unwrap(bound), open));
+
+  factory IDBKeyRange.bound(/*IDBKey*/ lower, /*IDBKey*/ upper,
+                            [bool lowerOpen = false, bool upperOpen = false]) =>
+      _wrap(new dom.IDBKeyRange.bound(_unwrap(lower), _unwrap(upper),
+                                      lowerOpen, upperOpen));
+}
+
 class _TypedArrayFactoryProvider {
 
   factory Float32Array(int length) => _F32(length);