Oilpan: Remove guardRef and guardDeref from TreeScope.

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index f58cf8bd9d9fedc616b166dee9c489bdf7a52341..ab289432e3ffd27ff53f5643c25282d27ec29382 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -376,7 +376,9 @@ DocumentVisibilityObserver::DocumentVisibilityObserver(Document& document)
 
 DocumentVisibilityObserver::~DocumentVisibilityObserver()
 {
+#if !ENABLE(OILPAN)
     unregisterObserver();
+#endif
 }
 
 void DocumentVisibilityObserver::unregisterObserver()
@@ -522,7 +524,11 @@ Document::~Document()
     ASSERT(m_ranges.isEmpty());
     ASSERT(!parentTreeScope());
     ASSERT(!hasGuardRefCount());
+#if !ENABLE(OILPAN)
+    // With oilpan the visibility obeservers and the document can die together
+    // at which point the weak collection of observers will not be empty.
     ASSERT(m_visibilityObservers.isEmpty());
+#endif
 
     if (m_templateDocument)
         m_templateDocument->m_templateDocumentHost = 0; // balanced in ensureTemplateDocument().
@@ -1419,8 +1425,8 @@ void Document::didChangeVisibilityState()
     dispatchEvent(Event::create(EventTypeNames::webkitvisibilitychange));
 
     PageVisibilityState state = pageVisibilityState();
-    HashSet<DocumentVisibilityObserver*>::const_iterator observerEnd = m_visibilityObservers.end();
-    for (HashSet<DocumentVisibilityObserver*>::const_iterator it = m_visibilityObservers.begin(); it != observerEnd; ++it)
+    WillBeHeapHashSet<RawPtrWillBeWeakMember<DocumentVisibilityObserver> >::const_iterator observerEnd = m_visibilityObservers.end();
+    for (WillBeHeapHashSet<RawPtrWillBeWeakMember<DocumentVisibilityObserver> >::const_iterator it = m_visibilityObservers.begin(); it != observerEnd; ++it)
         (*it)->didChangeVisibilityState(state);
 }
 
@@ -4763,7 +4769,7 @@ void Document::detachRange(Range* range)
     m_ranges.remove(range);
 }
 
-void Document::getCSSCanvasContext(const String& type, const String& name, int width, int height, bool& is2d, RefPtr<CanvasRenderingContext2D>& context2d, bool& is3d, RefPtr<WebGLRenderingContext>& context3d)
+void Document::getCSSCanvasContext(const String& type, const String& name, int width, int height, bool& is2d, RefPtrWillBeRawPtr<CanvasRenderingContext2D>& context2d, bool& is3d, RefPtrWillBeRawPtr<WebGLRenderingContext>& context3d)
 {
     HTMLCanvasElement& element = getCSSCanvasElement(name);
     element.setSize(IntSize(width, height));
@@ -5523,9 +5529,32 @@ void Document::invalidateNodeListCaches(const QualifiedName* attrName)
         (*it)->invalidateCache(attrName);
 }
 
+void Document::clearWeakMembers(Visitor* visitor)
+{
+    if (m_axObjectCache)
+        m_axObjectCache->clearWeakMembers(visitor);
+
+    if (m_markers)
+        m_markers->clearWeakMembers(visitor);
+
+    // FIXME: Oilpan: Use a weak counted set instead.
+    if (m_touchEventTargets) {
+        Vector<Node*> deadNodes;
+        for (TouchEventTargetSet::iterator it = m_touchEventTargets->begin(); it != m_touchEventTargets->end(); ++it) {
+            if (!visitor->isAlive(it->key))
+                deadNodes.append(it->key);
+        }
+        for (unsigned i = 0; i < deadNodes.size(); ++i)
+            didClearTouchEventHandlers(deadNodes[i]);
+    }
+}
+
 void Document::trace(Visitor* visitor)
 {
+    visitor->trace(m_visibilityObservers);
+    visitor->registerWeakMembers<Document, &Document::clearWeakMembers>(this);
     Supplementable<Document>::trace(visitor);
+    TreeScope::trace(visitor);
     ContainerNode::trace(visitor);
 }