Update PromiseRejectionEvent IDL to match latest spec

third_party/WebKit/Source/core/events/PromiseRejectionEvent.cpp

 // Copyright 2015 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 "config.h"
 #include "core/events/PromiseRejectionEvent.h"
 
 #include "bindings/core/v8/DOMWrapperWorld.h"
 
@@ skipping 26 matching lines @@
     // Return null when the promise is accessed by a different world than the world that created the promise.
     if (!m_scriptState || !m_scriptState->contextIsValid() || m_scriptState->world().worldId() != state->world().worldId())
         return ScriptPromise();
     return ScriptPromise(m_scriptState.get(), m_promise.newLocal(m_scriptState->isolate()));
 }
 
 ScriptValue PromiseRejectionEvent::reason(ScriptState* state) const
 {
     // Return null when the value is accessed by a different world than the world that created the value.
     if (m_reason.isEmpty() || !m_scriptState || !m_scriptState->contextIsValid() || m_scriptState->world().worldId() != state->world().worldId())
-        return ScriptValue(state, v8::Null(state->isolate()));
+        return ScriptValue(state, v8::Undefined(state->isolate()));
     return ScriptValue(m_scriptState.get(), m_reason.newLocal(m_scriptState->isolate()));
 }
 
 void PromiseRejectionEvent::setWrapperReference(v8::Isolate* isolate, const v8::Persistent<v8::Object>& wrapper)
 {
     // This might create cross world references. However, the regular code path
     // will not create them, and if we get a cross world reference here, the
     // worst thing is that the lifetime is too long (similar to what happens
     // for DOM trees).
     if (!m_promise.isEmpty())
@@ skipping 21 matching lines @@
 {
     data.GetParameter()->m_promise.clear();
 }
 
 void PromiseRejectionEvent::didCollectReason(const v8::WeakCallbackInfo<PromiseRejectionEvent>& data)
 {
     data.GetParameter()->m_reason.clear();
 }
 
 } // namespace blink