Implement author-constructible ReadableStream using V8 extras

third_party/WebKit/Source/core/streams/ReadableStream.idl

Index: third_party/WebKit/Source/core/streams/ReadableStream.idl
diff --git a/third_party/WebKit/Source/core/streams/ReadableStream.idl b/third_party/WebKit/Source/core/streams/ReadableStream.idl
index 33fbddc153a7d6508c76482eae7ab735bd8bdf9c..c4eca58eb076a63944bb41d0d4fab8344036dc6f 100644
--- a/third_party/WebKit/Source/core/streams/ReadableStream.idl
+++ b/third_party/WebKit/Source/core/streams/ReadableStream.idl
@@ -2,9 +2,14 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// This type is marked NoInterfaceObject while we work to replace it with the
+// V8 extras implementation. It is still used for now to implement fetch body
+// streams, and so we can't remove it quite yet.
+
 [
     GarbageCollected,
     Exposed=(Window,Worker),
+    NoInterfaceObject
 ] interface ReadableStream {
     [CallWith=ExecutionContext, RaisesException] ReadableStreamReader getReader();
     [CallWith=ScriptState] Promise<void> cancel(optional any reason);