Oilpan: add transition types to track interface objects.

Source/core/html/track/vtt/VTTRegion.h

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 17 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef VTTRegion_h
 #define VTTRegion_h
 
 #include "core/dom/ContextLifecycleObserver.h"
 #include "core/html/track/TextTrack.h"
 #include "platform/Timer.h"
 #include "platform/geometry/FloatPoint.h"
+#include "platform/heap/Handle.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/RefCounted.h"
 
 namespace WebCore {
 
 class ExceptionState;
 class HTMLDivElement;
 class VTTCueBox;
 class VTTScanner;
 
-class VTTRegion : public RefCounted<VTTRegion> {
+class VTTRegion FINAL : public RefCountedWillBeGarbageCollectedFinalized<VTTRegion> {
 public:
-    static PassRefPtr<VTTRegion> create()
+    static PassRefPtrWillBeRawPtr<VTTRegion> create()
     {
-        return adoptRef(new VTTRegion());
+        return adoptRefWillBeNoop(new VTTRegion());
     }
 
     virtual ~VTTRegion();
 
     TextTrack* track() const { return m_track; }
     void setTrack(TextTrack*);
 
     const String& id() const { return m_id; }
     void setId(const String&);
 
@@ skipping 24 matching lines @@
     void setRegionSettings(const String&);
 
     bool isScrollingRegion() { return m_scroll; }
 
     PassRefPtr<HTMLDivElement> getDisplayTree(Document&);
 
     void appendVTTCueBox(PassRefPtr<VTTCueBox>);
     void displayLastVTTCueBox();
     void willRemoveVTTCueBox(VTTCueBox*);
 
+    void trace(Visitor*);
+
 private:
     VTTRegion();
 
     void prepareRegionDisplayTree();
 
     // The timer is needed to continue processing when cue scrolling ended.
     void startTimer();
     void stopTimer();
     void scrollTimerFired(Timer<VTTRegion>*);
 
@@ skipping 23 matching lines @@
 
     // The cue container is the container that is scrolled up to obtain the
     // effect of scrolling cues when this is enabled for the regions.
     RefPtr<HTMLDivElement> m_cueContainer;
     RefPtr<HTMLDivElement> m_regionDisplayTree;
 
     // The member variable track can be a raw pointer as it will never
     // reference a destroyed TextTrack, as this member variable
     // is cleared in the TextTrack destructor and it is generally
     // set/reset within the addRegion and removeRegion methods.
-    TextTrack* m_track;
+    RawPtrWillBeMember<TextTrack> m_track;

[haraken, 2014/04/23 01:51:45]

Ditto. Probably this should be a WeakMember because the VTTRegion object can
outlive the TextTrack object if a JS wrapper holds the VTTRegion object.

[Mads Ager (chromium), 2014/04/23 05:59:38]

No, this is a raw pointer because it couldn't be a RefPtr because that would
lead to a ref cycle that would not be reclaimed. This should be a strong
pointer.

 
     // Keep track of the current numeric value of the css "top" property.
     double m_currentTop;
 
     // The timer is used to display the next cue line after the current one has
     // been displayed. It's main use is for scrolling regions and it triggers as
     // soon as the animation for rolling out one line has finished, but
     // currently it is used also for non-scrolling regions to use a single
     // code path.
     Timer<VTTRegion> m_scrollTimer;
 };
 
 } // namespace WebCore
 #endif