Enforce containing block requirement for IntersectionObserver.

third_party/WebKit/Source/core/dom/NodeIntersectionObserverData.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/NodeIntersectionObserverData.h"
 
 #include "core/dom/Document.h"
 #include "core/dom/IntersectionObservation.h"
 #include "core/dom/IntersectionObserver.h"
 #include "core/dom/IntersectionObserverController.h"
@@ skipping 28 matching lines @@
 }
 
 void NodeIntersectionObserverData::removeObservation(IntersectionObserver& observer)
 {
     m_intersectionObservations.remove(&observer);
 }
 
 void NodeIntersectionObserverData::activateValidIntersectionObservers(Node& node)
 {
     IntersectionObserverController& controller = node.document().ensureIntersectionObserverController();
-    // Activate observers for which node is root.
-    for (auto& observer : m_intersectionObservers) {
+    for (auto& observer : m_intersectionObservers)
         controller.addTrackedObserver(*observer);
-        observer->setActive(true);
-    }
-    // A document can be root, but not target.
-    if (node.isDocumentNode())
-        return;
-    // Active observers for which node is target.
-    for (auto& observation : m_intersectionObservations)
-        observation.value->setActive(observation.key->isDescendantOfRoot(&toElement(node)));
 }
 
 void NodeIntersectionObserverData::deactivateAllIntersectionObservers(Node& node)
 {
     node.document().ensureIntersectionObserverController().removeTrackedObserversForRoot(node);
-    for (auto& observer : m_intersectionObservers)
-        observer->setActive(false);
-    for (auto& observation : m_intersectionObservations)
-        observation.value->setActive(false);
 }
 
 #if !ENABLE(OILPAN)
 void NodeIntersectionObserverData::dispose()
 {
     HeapVector<Member<IntersectionObserver>> observersToDisconnect;
     copyToVector(m_intersectionObservers, observersToDisconnect);
     for (auto& observer : observersToDisconnect)
         observer->disconnect();
     ASSERT(m_intersectionObservers.isEmpty());
@@ skipping 13 matching lines @@
 #endif
 }
 
 DEFINE_TRACE(NodeIntersectionObserverData)
 {
     visitor->trace(m_intersectionObservers);
     visitor->trace(m_intersectionObservations);
 }
 
 } // namespace blink