TextTrackCue should check for non-NULL cue list pointer

Source/core/html/track/TextTrackCue.cpp

 /*
  * Copyright (C) 2011 Google Inc.  All rights reserved.
  * Copyright (C) 2011, 2012, 2013 Apple 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.
@@ skipping 462 matching lines @@
     cueWillChange();
     // Clear the document fragment but don't bother to create it again just yet as we can do that
     // when it is requested.
     m_webVTTNodeTree = 0;
     m_content = text;
     cueDidChange();
 }
 
 int TextTrackCue::cueIndex()
 {
-    if (m_cueIndex == invalidCueIndex)
-        m_cueIndex = track()->cues()->getCueIndex(this);
+    if (m_cueIndex == invalidCueIndex) {
+        if (TextTrackCueList* cues = track()->cues())

[scherkus (not reviewing), 2013/06/14 00:28:00]

I'm not sure if this is common Blink style, but it seems we could write this as:

if (m_cueIndex == invalidCueIndex && track()->cues())
    m_cueIndex = track()->cues()->getCueIndex(this);

[Matthew Heaney (Chromium), 2013/06/21 19:27:39]

I modified the code to match the coding style from a similar predicate in
another part in Blink (HTMLMediaElement::removeTrack()).

+            m_cueIndex = cues->getCueIndex(this);
+    }
 
     return m_cueIndex;
 }
 
 void TextTrackCue::invalidateCueIndex()
 {
     m_cueIndex = invalidCueIndex;
 }
 
 void TextTrackCue::createWebVTTNodeTree()
@@ skipping 688 matching lines @@
     if (m_cueSize != cue.size())
         return false;
     if (align() != cue.align())
         return false;
     
     return true;
 }
 
 } // namespace WebCore