Clean up HTMLTrackElement.kind invalid/missing value default handling

third_party/WebKit/Source/core/html/track/VideoTrack.h

Index: third_party/WebKit/Source/core/html/track/VideoTrack.h
diff --git a/third_party/WebKit/Source/core/html/track/VideoTrack.h b/third_party/WebKit/Source/core/html/track/VideoTrack.h
index 4040120a27393063ba590c6503c2ac5bd850d71d..5acc8425fbcff3775e2a99a9aa56963abf5e8a8d 100644
--- a/third_party/WebKit/Source/core/html/track/VideoTrack.h
+++ b/third_party/WebKit/Source/core/html/track/VideoTrack.h
@@ -17,7 +17,7 @@ class CORE_EXPORT VideoTrack final : public GarbageCollectedFinalized<VideoTrack
 public:
     static VideoTrack* create(const String& id, const AtomicString& kind, const AtomicString& label, const AtomicString& language, bool selected)
     {
-        return new VideoTrack(id, kind, label, language, selected);
+        return new VideoTrack(id, isValidKindKeyword(kind) ? kind : emptyAtom, label, language, selected);
     }
 
     ~VideoTrack() override;
@@ -43,10 +43,6 @@ public:
 private:
     VideoTrack(const String& id, const AtomicString& kind, const AtomicString& label, const AtomicString& language, bool selected);
 
-    // TrackBase
-    bool isValidKind(const AtomicString& kind) const override { return isValidKindKeyword(kind); }
-    AtomicString invalidValueDefaultKind() const override;
-
     bool m_selected;
 };