Fix HTMLMediaElement so that it doesn't add cues for disabled text tracks.

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 329bc95518761ac2cb4f1d7392f25049ead11455..068e4d18edbce8c15d661bcf04fa9db18b15d6a4 100644
--- a/Source/core/html/track/TextTrackCue.cpp
+++ b/Source/core/html/track/TextTrackCue.cpp
@@ -479,11 +479,8 @@ void TextTrackCue::setText(const String& text)
 
 int TextTrackCue::cueIndex()
 {
-    if (m_cueIndex == invalidCueIndex) {
-        TextTrackCueList* cues = track()->cues();
-        if (cues)
-            m_cueIndex = cues->getCueIndex(this);
-    }
+    if (m_cueIndex == invalidCueIndex)
+        m_cueIndex = track()->cues()->getCueIndex(this);
 
     return m_cueIndex;
 }
@@ -1191,4 +1188,3 @@ bool TextTrackCue::operator==(const TextTrackCue& cue) const
 }
 
 } // namespace WebCore
-