[WIP]Oilpan: checking for nearly-dead observers.

Source/core/page/PageLifecycleNotifier.cpp

Index: Source/core/page/PageLifecycleNotifier.cpp
diff --git a/Source/core/page/PageLifecycleNotifier.cpp b/Source/core/page/PageLifecycleNotifier.cpp
index 2a6f3869481dc57f8840bc785acf5f467f7ead2a..0bd9c0b239ec540953c2b2b0179fe36baf501563 100644
--- a/Source/core/page/PageLifecycleNotifier.cpp
+++ b/Source/core/page/PageLifecycleNotifier.cpp
@@ -34,15 +34,25 @@ namespace blink {
 void PageLifecycleNotifier::notifyPageVisibilityChanged()
 {
     TemporaryChange<IterationType> scope(m_iterating, IteratingOverAll);
-    for (PageLifecycleObserver* observer : m_observers)
+    for (PageLifecycleObserver* observer : m_observers) {
+#if !ENABLE(OILPAN)
+        if (!isObserverAlive(observer))
+            continue;
+#endif
         observer->pageVisibilityChanged();
+    }
 }
 
 void PageLifecycleNotifier::notifyDidCommitLoad(LocalFrame* frame)
 {
     TemporaryChange<IterationType> scope(m_iterating, IteratingOverAll);
-    for (PageLifecycleObserver* observer : m_observers)
+    for (PageLifecycleObserver* observer : m_observers) {
+#if !ENABLE(OILPAN)
+        if (!isObserverAlive(observer))
+            continue;
+#endif
         observer->didCommitLoad(frame);
+    }
 }
 
 } // namespace blink