TextTrackCue should check for non-NULL cue list pointer

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 feddf703d61798d5e37d42342ca1af9d5568615a..dcf9b1fe844b702c80bf001c71fe645233a60484 100644
--- a/Source/core/html/track/TextTrackCue.cpp
+++ b/Source/core/html/track/TextTrackCue.cpp
@@ -480,8 +480,10 @@ void TextTrackCue::setText(const String& text)
 
 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;
 }