Simplify LifecycleNotifier and Observer.

third_party/WebKit/Source/core/dom/Fullscreen.cpp

Index: third_party/WebKit/Source/core/dom/Fullscreen.cpp
diff --git a/third_party/WebKit/Source/core/dom/Fullscreen.cpp b/third_party/WebKit/Source/core/dom/Fullscreen.cpp
index ced95681a56b7399eb7cce903ca288c35b433681..56cd044146d6123cda566f9e60a3586254a33c3e 100644
--- a/third_party/WebKit/Source/core/dom/Fullscreen.cpp
+++ b/third_party/WebKit/Source/core/dom/Fullscreen.cpp
@@ -193,22 +193,10 @@ void Fullscreen::documentWasDetached()
     if (m_fullScreenLayoutObject)
         m_fullScreenLayoutObject->destroy();
 
-#if ENABLE(OILPAN)
     m_fullScreenElement = nullptr;
     m_fullScreenElementStack.clear();
-#endif
-
-}
 
-#if !ENABLE(OILPAN)
-void Fullscreen::documentWasDisposed()
-{
-    // NOTE: the context dispose phase is not supported in oilpan. Please
-    // consider using the detach phase instead.
-    m_fullScreenElement = nullptr;
-    m_fullScreenElementStack.clear();
 }
-#endif
 
 void Fullscreen::requestFullscreen(Element& element, RequestType requestType)
 {