Update Window API for CSSOM smooth scrolling to match the spec

Source/core/frame/ScrollToOptions.idl

Index: Source/core/frame/ScrollToOptions.idl
diff --git a/Source/core/frame/ScrollToOptions.idl b/Source/core/frame/ScrollToOptions.idl
new file mode 100644
index 0000000000000000000000000000000000000000..fd9c2b9f46341dd548f133aaa5880f4f8cb9b152
--- /dev/null
+++ b/Source/core/frame/ScrollToOptions.idl
@@ -0,0 +1,10 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Spec: http://http://dev.w3.org/csswg/cssom-view#extensions-to-the-window-interface
+
+dictionary ScrollToOptions : ScrollOptions {
+    double left;
+    double top;
+};