Remove dead code for reflected attributes on <audio>, <video> and <track>

Source/core/html/HTMLTrackElement.cpp

Index: Source/core/html/HTMLTrackElement.cpp
diff --git a/Source/core/html/HTMLTrackElement.cpp b/Source/core/html/HTMLTrackElement.cpp
index 02c8751f00b505c3cd9cc3c21c0624fd69c5f77d..4214e36684047ac1fdfb4e4488c2fee037539ab9 100644
--- a/Source/core/html/HTMLTrackElement.cpp
+++ b/Source/core/html/HTMLTrackElement.cpp
@@ -116,16 +116,6 @@ void HTMLTrackElement::parseAttribute(const QualifiedName& name, const AtomicStr
     HTMLElement::parseAttribute(name, value);
 }
 
-KURL HTMLTrackElement::src() const
-{
-    return document().completeURL(getAttribute(srcAttr));
-}
-
-void HTMLTrackElement::setSrc(const String& url)
-{
-    setAttribute(srcAttr, url);
-}
-
 String HTMLTrackElement::kind()
 {
     return track()->kind();