IntersectionObserver: discard notifications upon disconnect().

third_party/WebKit/Source/core/dom/IntersectionObserver.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/IntersectionObserver.h"
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "core/css/parser/CSSParserTokenRange.h"
 #include "core/css/parser/CSSTokenizer.h"
 #include "core/dom/Element.h"
@@ skipping 288 matching lines @@
   DOMHighResTimeStamp timestamp =
       DOMWindowPerformance::performance(*callbackDOMWindow)->now();
   for (auto& observation : m_observations)
     observation->computeIntersectionObservations(timestamp);
 }
 
 void IntersectionObserver::disconnect(ExceptionState& exceptionState) {
   for (auto& observation : m_observations)
     observation->disconnect();
   m_observations.clear();
+  m_entries.clear();
 }
 
 HeapVector<Member<IntersectionObserverEntry>> IntersectionObserver::takeRecords(
     ExceptionState& exceptionState) {
   HeapVector<Member<IntersectionObserverEntry>> entries;
   entries.swap(m_entries);
   return entries;
 }
 
 static void appendLength(StringBuilder& stringBuilder, const Length& length) {
@@ skipping 42 matching lines @@
 
 DEFINE_TRACE(IntersectionObserver) {
   visitor->template registerWeakMembers<
       IntersectionObserver, &IntersectionObserver::clearWeakMembers>(this);
   visitor->trace(m_callback);
   visitor->trace(m_observations);
   visitor->trace(m_entries);
 }
 
 }  // namespace blink