Encoding API: Add TextDecodeOptions and TextDecoderOptions

Source/modules/encoding/TextDecodeOptions.idl

Index: Source/modules/encoding/TextDecodeOptions.idl
diff --git a/Source/modules/webmidi/MIDIOptions.idl b/Source/modules/encoding/TextDecodeOptions.idl
similarity index 63%
copy from Source/modules/webmidi/MIDIOptions.idl
copy to Source/modules/encoding/TextDecodeOptions.idl
index 447e6cd464b5852dad136f1004b53ed490145511..a4e0974b5c067bc27e96d02afce969a09e66b446 100644
--- a/Source/modules/webmidi/MIDIOptions.idl
+++ b/Source/modules/encoding/TextDecodeOptions.idl
@@ -2,10 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// http://www.w3.org/TR/webmidi/#midioptions-dictionary
+// http://encoding.spec.whatwg.org/#textdecoder
 
 [
     GarbageCollected
-] dictionary MIDIOptions {
-    boolean sysex;
+] dictionary TextDecodeOptions {
+    boolean stream = false;
 };