Detach Event Listener Properties before moving Node.

third_party/WebKit/Source/core/dom/Node.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  *
@@ skipping 1790 matching lines @@
 }
 
 const AtomicString& Node::interfaceName() const {
   return EventTargetNames::Node;
 }
 
 ExecutionContext* Node::getExecutionContext() const {
   return document().contextDocument();
 }
 
+void Node::willMoveToNewDocument(Document& oldDocument, Document& newDocument) {
+  if (oldDocument == newDocument)
+    return;
+
+  if (oldDocument.frameHost()) {
+    oldDocument.frameHost()->eventHandlerRegistry().didMoveOutOfFrameHost(
+        *this);
+  }
+}
+
 void Node::didMoveToNewDocument(Document& oldDocument) {
   TreeScopeAdopter::ensureDidMoveToNewDocumentWasCalled(oldDocument);
 
   if (const EventTargetData* eventTargetData = this->eventTargetData()) {
     const EventListenerMap& listenerMap = eventTargetData->eventListenerMap;
     if (!listenerMap.isEmpty()) {
       for (const auto& type : listenerMap.eventTypes())
         document().addListenerTypeIfNeeded(type);
     }
   }
 
   oldDocument.markers().removeMarkers(this);
-  if (oldDocument.frameHost() && !document().frameHost())
-    oldDocument.frameHost()->eventHandlerRegistry().didMoveOutOfFrameHost(
-        *this);
-  else if (document().frameHost() && !oldDocument.frameHost())
+  if (document().frameHost()) {
+    DCHECK_NE(document().frameHost(), oldDocument.frameHost());

[bokan, 2017/01/13 18:35:10]

Can we assume this in general? What if you move between documents in the same
FrameHost? My comment was about avoiding the whole removing and adding to
eventHandlerRegistry if it's not going to change.

[wjmaclean, 2017/01/13 20:04:24]

Ha ha ... apparently not according to the bots!

But now I better understand what you intended, so I'm running a revised patch on
the bots.

     document().frameHost()->eventHandlerRegistry().didMoveIntoFrameHost(*this);
-  else if (oldDocument.frameHost() != document().frameHost())
-    EventHandlerRegistry::didMoveBetweenFrameHosts(
-        *this, oldDocument.frameHost(), document().frameHost());
+  }
 
   if (const HeapVector<TraceWrapperMember<MutationObserverRegistration>>*
           registry = mutationObserverRegistry()) {
     for (const auto& registration : *registry) {
       document().addMutationObserverTypes(registration->mutationTypes());
     }
   }
 
   if (transientMutationObserverRegistry()) {
     for (MutationObserverRegistration* registration :
@@ skipping 701 matching lines @@
   if (node) {
     std::stringstream stream;
     node->printNodePathTo(stream);
     LOG(INFO) << stream.str();
   } else {
     LOG(INFO) << "Cannot showNodePath for <null>";
   }
 }
 
 #endif