Introduce an injection point to configure the internal pointer of WeakPtr

third_party/WebKit/Source/core/dom/IntersectionObserverController.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/dom/IntersectionObserverController.h"
 
 #include "core/dom/Document.h"
 #include "core/dom/TaskRunnerHelper.h"
 #include "platform/TraceEvent.h"
 
@@ skipping 77 matching lines @@
         if (observer->rootNode() == &root)
             toRemove.append(observer);
     }
     m_trackedIntersectionObservers.removeAll(toRemove);
 }
 
 DEFINE_TRACE(IntersectionObserverController)
 {
     visitor->trace(m_trackedIntersectionObservers);
     visitor->trace(m_pendingIntersectionObservers);
+    visitor->trace(m_weakPtrFactory);
     ActiveDOMObject::trace(visitor);
 }
 
 } // namespace blink