Make atob() / btoa() argument non optional

Source/core/page/WindowBase64.idl

Index: Source/core/page/WindowBase64.idl
diff --git a/Source/modules/indexeddb/WindowIndexedDatabase.idl b/Source/core/page/WindowBase64.idl
similarity index 84%
copy from Source/modules/indexeddb/WindowIndexedDatabase.idl
copy to Source/core/page/WindowBase64.idl
index 3823e4f2a5e7402f845bb82fcbbbaa30ce0a95e6..40b1ae642e901fc8a86a39b9e9f29b9881c90158 100644
--- a/Source/modules/indexeddb/WindowIndexedDatabase.idl
+++ b/Source/core/page/WindowBase64.idl
@@ -1,6 +1,7 @@
 /*
  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2011 Google Inc. All rights reserved.
+ * Copyright (C) 2013 Samsung Electronics. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -25,9 +26,8 @@
  */
 
 [
-    ImplementedAs=DOMWindowIndexedDatabase
-] partial interface Window {
-    [ImplementedAs=indexedDB,MeasureAs=PrefixedIndexedDB] readonly attribute IDBFactory webkitIndexedDB;
-
-    [MeasureAs=UnprefixedIndexedDB] readonly attribute IDBFactory indexedDB;
+    NoInterfaceObject
+] interface WindowBase64 {
+    [RaisesException] DOMString atob(DOMString string);
+    [RaisesException] DOMString btoa(DOMString string);
 };