Oilpan: add transition types to track interface objects.

Source/core/html/HTMLMediaElement.cpp

Index: Source/core/html/HTMLMediaElement.cpp
diff --git a/Source/core/html/HTMLMediaElement.cpp b/Source/core/html/HTMLMediaElement.cpp
index e3552279e73c85d31676bb58f87f3071accbc726..007d436e12893afb6fac789ed271dbfa7eb46ec0 100644
--- a/Source/core/html/HTMLMediaElement.cpp
+++ b/Source/core/html/HTMLMediaElement.cpp
@@ -306,9 +306,6 @@ HTMLMediaElement::~HTMLMediaElement()
 
     setShouldDelayLoadEvent(false);
 
-    if (m_textTracks)

[Mads Ager (chromium), 2014/04/22 13:07:15]

We should probably wrap this in #if !ENABLE(OILPAN) instead of deleting it. It
is probably still needed for non-oilpan builds?

[sof, 2014/04/22 14:02:48]

The media element is the sole creator and owner of TextTrackList instances, so
when it deref()s, the object will be destructed. Unless its destructor makes use
of the media element, this ought to be safe, right?

[Mads Ager (chromium), 2014/04/22 14:17:59]

No, I don't think it is. It is only safe if they always live and die together.
We make that happen in the oilpan build, but it is not the case in the
non-oilpan build. There can be JavaScript wrappers for the TextTrackList that
can out-live the owner I think. Therefore, I think it is extremely dangerous for
us to remove clearing of pointers from the non-oilpan build. We are likely to
introduce security issues where we allow dangling pointers.

I would strongly prefer that we ifdef out clearing of pointers only for the
oilpan build. We have to be 100% sure that we can leave out the clearing in the
non-oilpan build. I'm not at all sure in these cases and I think that because of
JavaScript wrappers for these objects we need to keep the clearing.

-        m_textTracks->clearOwner();
-
     if (m_mediaController) {
         m_mediaController->removeMediaElement(this);
         m_mediaController = nullptr;
@@ -1261,7 +1258,7 @@ void HTMLMediaElement::textTrackRemoveCues(TextTrack*, const TextTrackCueList* c
         textTrackRemoveCue(cues->item(i)->track(), cues->item(i));
 }
 
-void HTMLMediaElement::textTrackAddCue(TextTrack* track, PassRefPtr<TextTrackCue> cue)
+void HTMLMediaElement::textTrackAddCue(TextTrack* track, PassRefPtrWillBeRawPtr<TextTrackCue> cue)
 {
     if (track->mode() == TextTrack::disabledKeyword())
         return;
@@ -1276,7 +1273,7 @@ void HTMLMediaElement::textTrackAddCue(TextTrack* track, PassRefPtr<TextTrackCue
     updateActiveTextTrackCues(currentTime());
 }
 
-void HTMLMediaElement::textTrackRemoveCue(TextTrack*, PassRefPtr<TextTrackCue> cue)
+void HTMLMediaElement::textTrackRemoveCue(TextTrack*, PassRefPtrWillBeRawPtr<TextTrackCue> cue)
 {
     // Negative duration cues need to be treated in the interval tree as
     // zero-length cues.
@@ -2224,7 +2221,7 @@ void HTMLMediaElement::mediaPlayerDidAddTextTrack(WebInbandTextTrack* webTrack)
 {
     // 4.8.10.12.2 Sourcing in-band text tracks
     // 1. Associate the relevant data with a new text track and its corresponding new TextTrack object.
-    RefPtr<InbandTextTrack> textTrack = InbandTextTrack::create(document(), webTrack);
+    RefPtrWillBeRawPtr<InbandTextTrack> textTrack = InbandTextTrack::create(document(), webTrack);
 
     // 2. Set the new text track's kind, label, and language based on the semantics of the relevant data,
     // as defined by the relevant specification. If there is no label in that data, then the label must
@@ -2259,7 +2256,7 @@ void HTMLMediaElement::mediaPlayerDidRemoveTextTrack(WebInbandTextTrack* webTrac
 
     // This cast is safe because we created the InbandTextTrack with the WebInbandTextTrack
     // passed to mediaPlayerDidAddTextTrack.
-    RefPtr<InbandTextTrack> textTrack = static_cast<InbandTextTrack*>(webTrack->client());
+    RefPtrWillBeRawPtr<InbandTextTrack> textTrack = static_cast<InbandTextTrack*>(webTrack->client());
     if (!textTrack)
         return;
 
@@ -2296,7 +2293,7 @@ void HTMLMediaElement::forgetResourceSpecificTracks()
     }
 }
 
-PassRefPtr<TextTrack> HTMLMediaElement::addTextTrack(const AtomicString& kind, const AtomicString& label, const AtomicString& language, ExceptionState& exceptionState)
+PassRefPtrWillBeRawPtr<TextTrack> HTMLMediaElement::addTextTrack(const AtomicString& kind, const AtomicString& label, const AtomicString& language, ExceptionState& exceptionState)
 {
     // 4.8.10.12.4 Text track API
     // The addTextTrack(kind, label, language) method of media elements, when invoked, must run the following steps:
@@ -2313,7 +2310,7 @@ PassRefPtr<TextTrack> HTMLMediaElement::addTextTrack(const AtomicString& kind, c
 
     // 5. Create a new text track corresponding to the new object, and set its text track kind to kind, its text
     // track label to label, its text track language to language...
-    RefPtr<TextTrack> textTrack = TextTrack::create(document(), kind, label, language);
+    RefPtrWillBeRawPtr<TextTrack> textTrack = TextTrack::create(document(), kind, label, language);
 
     // Note, due to side effects when changing track parameters, we have to
     // first append the track to the text track list.
@@ -2344,7 +2341,7 @@ void HTMLMediaElement::didAddTrackElement(HTMLTrackElement* trackElement)
     // When a track element's parent element changes and the new parent is a media element,
     // then the user agent must add the track element's corresponding text track to the
     // media element's list of text tracks ... [continues in TextTrackList::append]
-    RefPtr<TextTrack> textTrack = trackElement->track();
+    RefPtrWillBeRawPtr<TextTrack> textTrack = trackElement->track();
     if (!textTrack)
         return;
 
@@ -2366,7 +2363,7 @@ void HTMLMediaElement::didRemoveTrackElement(HTMLTrackElement* trackElement)
     WTF_LOG(Media, "HTMLMediaElement::didRemoveTrackElement - 'src' is %s", urlForLoggingMedia(url).utf8().data());
 #endif
 
-    RefPtr<TextTrack> textTrack = trackElement->track();
+    RefPtrWillBeRawPtr<TextTrack> textTrack = trackElement->track();
     if (!textTrack)
         return;
 
@@ -2428,13 +2425,13 @@ void HTMLMediaElement::configureTextTrackGroup(const TrackGroup& group)
     Settings* settings = document().settings();
 
     // First, find the track in the group that should be enabled (if any).
-    Vector<RefPtr<TextTrack> > currentlyEnabledTracks;
-    RefPtr<TextTrack> trackToEnable;
-    RefPtr<TextTrack> defaultTrack;
-    RefPtr<TextTrack> fallbackTrack;
+    WillBeHeapVector<RefPtrWillBeMember<TextTrack> > currentlyEnabledTracks;
+    RefPtrWillBeRawPtr<TextTrack> trackToEnable = nullptr;
+    RefPtrWillBeRawPtr<TextTrack> defaultTrack = nullptr;
+    RefPtrWillBeRawPtr<TextTrack> fallbackTrack = nullptr;
     int highestTrackScore = 0;
     for (size_t i = 0; i < group.tracks.size(); ++i) {
-        RefPtr<TextTrack> textTrack = group.tracks[i];
+        RefPtrWillBeRawPtr<TextTrack> textTrack = group.tracks[i];
 
         if (m_processingPreferenceChange && textTrack->mode() == TextTrack::showingKeyword())
             currentlyEnabledTracks.append(textTrack);
@@ -2480,7 +2477,7 @@ void HTMLMediaElement::configureTextTrackGroup(const TrackGroup& group)
 
     if (currentlyEnabledTracks.size()) {
         for (size_t i = 0; i < currentlyEnabledTracks.size(); ++i) {
-            RefPtr<TextTrack> textTrack = currentlyEnabledTracks[i];
+            RefPtrWillBeRawPtr<TextTrack> textTrack = currentlyEnabledTracks[i];
             if (textTrack != trackToEnable)
                 textTrack->setMode(TextTrack::disabledKeyword());
         }
@@ -2502,7 +2499,7 @@ void HTMLMediaElement::configureTextTracks()
         return;
 
     for (size_t i = 0; i < m_textTracks->length(); ++i) {
-        RefPtr<TextTrack> textTrack = m_textTracks->item(i);
+        RefPtrWillBeRawPtr<TextTrack> textTrack = m_textTracks->item(i);
         if (!textTrack)
             continue;
 
@@ -3391,7 +3388,7 @@ void HTMLMediaElement::markCaptionAndSubtitleTracksAsUnconfigured()
     // captions and non-default tracks should be displayed based on language
     // preferences if the user has turned captions on).
     for (unsigned i = 0; i < m_textTracks->length(); ++i) {
-        RefPtr<TextTrack> textTrack = m_textTracks->item(i);
+        RefPtrWillBeRawPtr<TextTrack> textTrack = m_textTracks->item(i);
         String kind = textTrack->kind();
 
         if (kind == TextTrack::subtitlesKeyword() || kind == TextTrack::captionsKeyword())
@@ -3644,6 +3641,8 @@ bool HTMLMediaElement::isInteractiveContent() const
 
 void HTMLMediaElement::trace(Visitor* visitor)
 {
+    visitor->trace(m_textTracks);
+    visitor->trace(m_textTracksWhenResourceSelectionBegan);
     Supplementable<HTMLMediaElement>::trace(visitor);
     HTMLElement::trace(visitor);
 }