Add initial Blink-side support for the Screen Orientation API

Source/modules/screen_orientation/ScreenOrientation.idl

Index: Source/modules/screen_orientation/ScreenOrientation.idl
diff --git a/Source/modules/screen_orientation/ScreenOrientation.idl b/Source/modules/screen_orientation/ScreenOrientation.idl
new file mode 100644
index 0000000000000000000000000000000000000000..6fc0d5db2f9bb6705e435d9bb78df79f39c6a761
--- /dev/null
+++ b/Source/modules/screen_orientation/ScreenOrientation.idl
@@ -0,0 +1,15 @@
+// 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.
+
+[
+    RuntimeEnabled=ScreenOrientation
+] partial interface Screen {
+    readonly attribute DOMString orientation;
+
+    boolean lockOrientation(sequence<DOMString> orientations);
+    boolean lockOrientation(DOMString orientation);
+
+    void unlockOrientation();
+    attribute EventHandler onorientationchange;
+};