Deprecate the TextTrackCue constructor

Source/core/frame/UseCounter.cpp

Index: Source/core/frame/UseCounter.cpp
diff --git a/Source/core/frame/UseCounter.cpp b/Source/core/frame/UseCounter.cpp
index cd883f643762d9c817da07a98fc26117fd168887..07b07f83c8eb293555ecefe6e48b9d55a4fc1a30 100644
--- a/Source/core/frame/UseCounter.cpp
+++ b/Source/core/frame/UseCounter.cpp
@@ -688,6 +688,9 @@ String UseCounter::deprecationMessage(Feature feature)
     case SVGElementGetPresentationAttribute:
         return "CSSValue and SVGElement.getPresentationAttribute are deprecated. Please use getPropertyValue and parse the return value instead.";
 
+    case TextTrackCueConstructor:
+        return "The 'TextTrackCue' constructor is deprecated. Please use 'VTTCue' instead.";
+
     // Features that aren't deprecated don't have a deprecation message.
     default:
         return String();