Oilpan: Remove guardRef and guardDeref from TreeScope.

Source/core/html/HTMLMediaElement.cpp

 /*
  * Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 104 matching lines @@
 // fair amount of overhead and logging.
 #define LOG_CACHED_TIME_WARNINGS 0
 #endif
 
 // URL protocol used to signal that the media source API is being used.
 static const char mediaSourceBlobProtocol[] = "blob";
 
 using namespace HTMLNames;
 using namespace std;
 
-typedef HashMap<Document*, HashSet<HTMLMediaElement*> > DocumentElementSetMap;
+typedef WillBeHeapHashSet<RawPtrWillBeWeakMember<HTMLMediaElement> > WeakMediaElementSet;
+typedef WillBeHeapHashMap<RawPtrWillBeWeakMember<Document>, WeakMediaElementSet> DocumentElementSetMap;
 static DocumentElementSetMap& documentToElementSetMap()
 {
+#if ENABLE(OILPAN)
+    DEFINE_STATIC_LOCAL(Persistent<DocumentElementSetMap>, map, (new DocumentElementSetMap()));
+    return *map;
+#else
     DEFINE_STATIC_LOCAL(DocumentElementSetMap, map, ());
     return map;
+#endif

[haraken, 2014/04/25 14:30:32]

Nit: We've been using #if for this pattern in a lot of places. We should
consider adding a WILL_BE macro in a follow-up.

[Mads Ager (chromium), 2014/04/28 09:45:21]

Yes, we should see what we can do with these. The thing that is annoying here is
the difference in the '*' in the return.

 }
 
 static void addElementToDocumentMap(HTMLMediaElement* element, Document* document)
 {
     DocumentElementSetMap& map = documentToElementSetMap();
-    HashSet<HTMLMediaElement*> set = map.take(document);
+    WeakMediaElementSet set = map.take(document);
     set.add(element);
     map.add(document, set);
 }
 
 static void removeElementFromDocumentMap(HTMLMediaElement* element, Document* document)
 {
     DocumentElementSetMap& map = documentToElementSetMap();
-    HashSet<HTMLMediaElement*> set = map.take(document);
+    WeakMediaElementSet set = map.take(document);
     set.remove(element);
     if (!set.isEmpty())
         map.add(document, set);
 }
 
 class TrackDisplayUpdateScope {
 public:
     TrackDisplayUpdateScope(HTMLMediaElement* mediaElement)
     {
         m_mediaElement = mediaElement;
@@ skipping 157 matching lines @@
         m_textTracks->clearOwner();
 #endif
 
     if (m_mediaController) {
         m_mediaController->removeMediaElement(this);
         m_mediaController = nullptr;
     }
 
     closeMediaSource();
 
+#if !ENABLE(OILPAN)
     removeElementFromDocumentMap(this, &document());
+#endif
 
     // Destroying the player may cause a resource load to be canceled,
     // which could result in userCancelledLoad() being called back.
     // Setting m_completelyLoaded ensures that such a call will not cause
     // us to dispatch an abort event, which would result in a crash.
     // See http://crbug.com/233654 for more details.
     m_completelyLoaded = true;
 
+    // With Oilpan load events on the Document are always delayed during
+    // sweeping so we don't need to explicitly increment and decrement
+    // load event delay counts.
+#if !ENABLE(OILPAN)
     // Destroying the player may cause a resource load to be canceled,
     // which could result in Document::dispatchWindowLoadEvent() being
     // called via ResourceFetch::didLoadResource() then
     // FrameLoader::loadDone(). To prevent load event dispatching during
     // object destruction, we use Document::incrementLoadEventDelayCount().
     // See http://crbug.com/275223 for more details.
     document().incrementLoadEventDelayCount();
+#endif
 
     clearMediaPlayerAndAudioSourceProviderClient();
 
+#if !ENABLE(OILPAN)
     document().decrementLoadEventDelayCount();
+#endif
 }
 
 void HTMLMediaElement::didMoveToNewDocument(Document& oldDocument)
 {
     WTF_LOG(Media, "HTMLMediaElement::didMoveToNewDocument");
 
     if (m_shouldDelayLoadEvent) {
         document().incrementLoadEventDelayCount();
         // Note: Keeping the load event delay count increment on oldDocument that was added
         // when m_shouldDelayLoadEvent was set so that destruction of m_player can not
@@ skipping 3120 matching lines @@
     // 1. Let m [this] be the media element in question.
     // 2. Let m have no current media controller, if it currently has one.
     setControllerInternal(nullptr);
 
     // 3. If m's mediagroup attribute is being removed, then abort these steps.
     if (group.isNull() || group.isEmpty())
         return;
 
     // 4. If there is another media element whose Document is the same as m's Document (even if one or both
     // of these elements are not actually in the Document),
-    HashSet<HTMLMediaElement*> elements = documentToElementSetMap().get(&document());
-    for (HashSet<HTMLMediaElement*>::iterator i = elements.begin(); i != elements.end(); ++i) {
+    WeakMediaElementSet elements = documentToElementSetMap().get(&document());
+    for (WeakMediaElementSet::iterator i = elements.begin(); i != elements.end(); ++i) {
         if (*i == this)
             continue;
 
         // and which also has a mediagroup attribute, and whose mediagroup attribute has the same value as
         // the new value of m's mediagroup attribute,
         if ((*i)->mediaGroup() == group) {
             //  then let controller be that media element's current media controller.
             setControllerInternal((*i)->controller());
             return;
         }
@@ skipping 140 matching lines @@
 
 void HTMLMediaElement::trace(Visitor* visitor)
 {
     visitor->trace(m_textTracks);
     visitor->trace(m_textTracksWhenResourceSelectionBegan);
     Supplementable<HTMLMediaElement>::trace(visitor);
     HTMLElement::trace(visitor);
 }
 
 }