Rework dispatchEvent so it is consistent for isTrusted support.

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 f1fcc51e0b5399d7cd04a4e9ea3924b5f9af845d..d8e5a2bb4b5fda17306534972a92c1f630f391af 100644
--- a/Source/core/html/track/TextTrackCue.cpp
+++ b/Source/core/html/track/TextTrackCue.cpp
@@ -137,13 +137,13 @@ unsigned TextTrackCue::cueIndex()
     return m_cueIndex;
 }
 
-bool TextTrackCue::dispatchEvent(PassRefPtrWillBeRawPtr<Event> event)
+bool TextTrackCue::dispatchEventInternal(PassRefPtrWillBeRawPtr<Event> event)
 {
     // When a TextTrack's mode is disabled: no cues are active, no events fired.
     if (!track() || track()->mode() == TextTrack::disabledKeyword())
         return false;
 
-    return EventTarget::dispatchEvent(event);
+    return EventTarget::dispatchEventInternal(event);
 }
 
 const AtomicString& TextTrackCue::interfaceName() const