Support text track selection in video controls

third_party/WebKit/Source/core/html/track/TextTrack.cpp

Index: third_party/WebKit/Source/core/html/track/TextTrack.cpp
diff --git a/third_party/WebKit/Source/core/html/track/TextTrack.cpp b/third_party/WebKit/Source/core/html/track/TextTrack.cpp
index 26858a7f9bc763a45be57a13478bd375195e606e..259ac3fe8444458792a82f92fa8fd00b825b5c06 100644
--- a/third_party/WebKit/Source/core/html/track/TextTrack.cpp
+++ b/third_party/WebKit/Source/core/html/track/TextTrack.cpp
@@ -414,7 +414,7 @@ void TextTrack::invalidateTrackIndex()
     m_renderedTrackIndex = invalidTrackIndex;
 }
 
-bool TextTrack::isRendered()
+bool TextTrack::isRendered() const
 {
     if (kind() != captionsKeyword() && kind() != subtitlesKeyword())
         return false;
@@ -425,6 +425,18 @@ bool TextTrack::isRendered()
     return true;
 }
 
+bool TextTrack::canBeRendered() const
+{
+    // A track can be displayed when it's of kind captions or subtitles and hasn't failed to load.
+    if (kind() != captionsKeyword() && kind() != subtitlesKeyword())
+        return false;
+
+    if (getReadinessState() == FailedToLoad)
+        return false;
+
+    return true;
+}
+
 TextTrackCueList* TextTrack::ensureTextTrackCueList()
 {
     if (!m_cues)