Reflect recent spec changes to V8 Extra ReadableStream impl

third_party/WebKit/Source/core/streams/UnderlyingSourceBase.cpp

 // Copyright 2016 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.
 
 #include "core/streams/UnderlyingSourceBase.h"
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptState.h"
 #include "bindings/core/v8/ScriptValue.h"
 #include "core/streams/ReadableStreamController.h"
 #include <v8.h>
 
 namespace blink {
 
-ScriptPromise UnderlyingSourceBase::startWrapper(ScriptState* scriptState, ScriptValue stream)
+ScriptPromise UnderlyingSourceBase::startWrapper(ScriptState* scriptState, ScriptValue jsController)
 {
     // Cannot call start twice (e.g., cannot use the same UnderlyingSourceBase to construct multiple streams)
     ASSERT(!m_controller);
 
-    // In ReadableStream.js, we special-case externally-controlled streams by having them pass themselves to start
-    // as the first argument. This allows us to create a ReadableStreamController.
-
-    m_controller = new ReadableStreamController(stream);
+    m_controller = new ReadableStreamController(jsController);
 
     return start(scriptState);
 }
 
 ScriptPromise UnderlyingSourceBase::start(ScriptState* scriptState)
 {
     return ScriptPromise::castUndefined(scriptState);
 }
 
 ScriptPromise UnderlyingSourceBase::pull(ScriptState* scriptState)
@@ skipping 37 matching lines @@
     m_controller.clear();
 }
 
 DEFINE_TRACE(UnderlyingSourceBase)
 {
     ActiveDOMObject::trace(visitor);
     visitor->trace(m_controller);
 }
 
 } // namespace blink