Remove DocumentVisibilityObserver

sky/engine/core/dom/Document.cpp

Index: sky/engine/core/dom/Document.cpp
diff --git a/sky/engine/core/dom/Document.cpp b/sky/engine/core/dom/Document.cpp
index 2a67e22582e73ae151a8e40f86e5450f5f622d68..f12929b3fa9cf9aebfa2bafaa7325ffd53faef08 100644
--- a/sky/engine/core/dom/Document.cpp
+++ b/sky/engine/core/dom/Document.cpp
@@ -242,41 +242,6 @@ static WeakDocumentSet& liveDocumentSet()
 }
 #endif
 
-DocumentVisibilityObserver::DocumentVisibilityObserver(Document& document)
-    : m_document(nullptr)
-{
-    registerObserver(document);
-}
-
-DocumentVisibilityObserver::~DocumentVisibilityObserver()
-{
-#if !ENABLE(OILPAN)
-    unregisterObserver();
-#endif
-}
-
-void DocumentVisibilityObserver::unregisterObserver()
-{
-    if (m_document) {
-        m_document->unregisterVisibilityObserver(this);
-        m_document = nullptr;
-    }
-}
-
-void DocumentVisibilityObserver::registerObserver(Document& document)
-{
-    ASSERT(!m_document);
-    m_document = &document;
-    if (m_document)
-        m_document->registerVisibilityObserver(this);
-}
-
-void DocumentVisibilityObserver::setObservedDocument(Document& document)
-{
-    unregisterObserver();
-    registerObserver(document);
-}
-
 Document::Document(const DocumentInit& initializer, DocumentClassFlags documentClasses)
     : ContainerNode(0, CreateDocument)
     , TreeScope(*this)
@@ -351,11 +316,6 @@ Document::~Document()
 #if !ENABLE(OILPAN)
     ASSERT(m_ranges.isEmpty());
     ASSERT(!hasGuardRefCount());
-    // With Oilpan, either the document outlives the visibility observers
-    // or the visibility observers and the document die in the same GC round.
-    // When they die in the same GC round, the list of visibility observers
-    // will not be empty on Document destruction.
-    ASSERT(m_visibilityObservers.isEmpty());
 
     if (m_templateDocument)
         m_templateDocument->m_templateDocumentHost = nullptr; // balanced in ensureTemplateDocument().
@@ -949,25 +909,6 @@ bool Document::hidden() const
 void Document::didChangeVisibilityState()
 {
     dispatchEvent(Event::create(EventTypeNames::visibilitychange));
-    // Also send out the deprecated version until it can be removed.
-    dispatchEvent(Event::create(EventTypeNames::webkitvisibilitychange));
-
-    PageVisibilityState state = pageVisibilityState();
-    DocumentVisibilityObserverSet::const_iterator observerEnd = m_visibilityObservers.end();
-    for (DocumentVisibilityObserverSet::const_iterator it = m_visibilityObservers.begin(); it != observerEnd; ++it)
-        (*it)->didChangeVisibilityState(state);
-}
-
-void Document::registerVisibilityObserver(DocumentVisibilityObserver* observer)
-{
-    ASSERT(!m_visibilityObservers.contains(observer));
-    m_visibilityObservers.add(observer);
-}
-
-void Document::unregisterVisibilityObserver(DocumentVisibilityObserver* observer)
-{
-    ASSERT(m_visibilityObservers.contains(observer));
-    m_visibilityObservers.remove(observer);
 }
 
 String Document::nodeName() const