Oilpan: support observer retirement during lifetime notifications.

Source/core/frame/DOMWindowLifecycleNotifier.cpp

Index: Source/core/frame/DOMWindowLifecycleNotifier.cpp
diff --git a/Source/core/frame/DOMWindowLifecycleNotifier.cpp b/Source/core/frame/DOMWindowLifecycleNotifier.cpp
index 0bf68af63befb4c417e068c7c83e482e62bd660b..5f525b66cd0d3fd739d7eac96a3b0ade3423d5cf 100644
--- a/Source/core/frame/DOMWindowLifecycleNotifier.cpp
+++ b/Source/core/frame/DOMWindowLifecycleNotifier.cpp
@@ -34,22 +34,64 @@ namespace blink {
 void DOMWindowLifecycleNotifier::notifyAddEventListener(LocalDOMWindow* window, const AtomicString& eventType)
 {
     TemporaryChange<IterationType> scope(m_iterating, IteratingOverAll);
+#if !ENABLE(OILPAN)
+    // Notifications perform unknown amounts of heap allocations,
+    // which might trigger (conservative) GCs. This will flush out
+    // dead observers, causing the _non-heap_ set be updated. Snapshot
+    // the observers and explicitly check if they're still alive before
+    // notifying.
+    Vector<RawPtr<DOMWindowLifecycleObserver>> snapshotOfObservers;
+    copyToVector(m_observers, snapshotOfObservers);
+    for (DOMWindowLifecycleObserver* observer : snapshotOfObservers) {
+        if (m_observers.contains(observer))
+            observer->didAddEventListener(window, eventType);
+    }
+#else
     for (DOMWindowLifecycleObserver* observer : m_observers)
         observer->didAddEventListener(window, eventType);
+#endif
 }
 
 void DOMWindowLifecycleNotifier::notifyRemoveEventListener(LocalDOMWindow* window, const AtomicString& eventType)
 {
     TemporaryChange<IterationType> scope(m_iterating, IteratingOverAll);
+#if !ENABLE(OILPAN)
+    // Notifications perform unknown amounts of heap allocations,
+    // which might trigger (conservative) GCs. This will flush out
+    // dead observers, causing the _non-heap_ set be updated. Snapshot
+    // the observers and explicitly check if they're still alive before
+    // notifying.
+    Vector<RawPtr<DOMWindowLifecycleObserver>> snapshotOfObservers;
+    copyToVector(m_observers, snapshotOfObservers);
+    for (DOMWindowLifecycleObserver* observer : snapshotOfObservers) {
+        if (m_observers.contains(observer))
+            observer->didRemoveEventListener(window, eventType);
+    }
+#else
     for (DOMWindowLifecycleObserver* observer : m_observers)
         observer->didRemoveEventListener(window, eventType);
+#endif
 }
 
 void DOMWindowLifecycleNotifier::notifyRemoveAllEventListeners(LocalDOMWindow* window)
 {
     TemporaryChange<IterationType> scope(m_iterating, IteratingOverAll);
+#if !ENABLE(OILPAN)
+    // Notifications perform unknown amounts of heap allocations,
+    // which might trigger (conservative) GCs. This will flush out
+    // dead observers, causing the _non-heap_ set be updated. Snapshot
+    // the observers and explicitly check if they're still alive before
+    // notifying.
+    Vector<RawPtr<DOMWindowLifecycleObserver>> snapshotOfObservers;
+    copyToVector(m_observers, snapshotOfObservers);
+    for (DOMWindowLifecycleObserver* observer : snapshotOfObservers) {
+        if (m_observers.contains(observer))
+            observer->didRemoveAllEventListeners(window);
+    }
+#else
     for (DOMWindowLifecycleObserver* observer : m_observers)
         observer->didRemoveAllEventListeners(window);
+#endif
 }
 
 } // namespace blink