Oilpan: Replace most of RefPtrs for Event objects with oilpan's transition types

Source/core/html/track/TextTrackCue.cpp

Index: Source/core/html/track/TextTrackCue.cpp
diff --git a/Source/core/html/track/TextTrackCue.cpp b/Source/core/html/track/TextTrackCue.cpp
index a89b46299beec8a669fe564ad6cb41860f6ddf18..ebf262f9b282d4d7db3b120dd822398f4e87a550 100644
--- a/Source/core/html/track/TextTrackCue.cpp
+++ b/Source/core/html/track/TextTrackCue.cpp
@@ -146,7 +146,7 @@ void TextTrackCue::invalidateCueIndex()
     m_cueIndex = invalidCueIndex;
 }
 
-bool TextTrackCue::dispatchEvent(PassRefPtr<Event> event)
+bool TextTrackCue::dispatchEvent(PassRefPtrWillBeRawPtr<Event> event)
 {
     // When a TextTrack's mode is disabled: no cues are active, no events fired.
     if (!track() || track()->mode() == TextTrack::disabledKeyword())