Remove the HTMLVideoElement-specific prefixed fullscreen API

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 b51203fe502d723e6d700f48844054ffd1d2f30c..c87393d31a2d76289c742855be00163accd66e10 100644
--- a/Source/core/frame/UseCounter.cpp
+++ b/Source/core/frame/UseCounter.cpp
@@ -664,24 +664,6 @@ String UseCounter::deprecationMessage(Feature feature)
     case TextTrackCueConstructor:
         return "The 'TextTrackCue' constructor is deprecated. Please use 'VTTCue' instead.";
 
-    case PrefixedVideoSupportsFullscreen:
-        return "'HTMLVideoElement.webkitSupportsFullscreen' is deprecated. Its value is true if the video is loaded.";
-
-    case PrefixedVideoDisplayingFullscreen:
-        return "'HTMLVideoElement.webkitDisplayingFullscreen' is deprecated. Please use the 'fullscreenchange' and 'webkitfullscreenchange' events instead.";
-
-    case PrefixedVideoEnterFullscreen:
-        return "'HTMLVideoElement.webkitEnterFullscreen()' is deprecated. Please use 'Element.requestFullscreen()' and 'Element.webkitRequestFullscreen()' instead.";
-
-    case PrefixedVideoExitFullscreen:
-        return "'HTMLVideoElement.webkitExitFullscreen()' is deprecated. Please use 'Document.exitFullscreen()' and 'Document.webkitExitFullscreen()' instead.";
-
-    case PrefixedVideoEnterFullScreen:
-        return "'HTMLVideoElement.webkitEnterFullScreen()' is deprecated. Please use 'Element.requestFullscreen()' and 'Element.webkitRequestFullscreen()' instead.";
-
-    case PrefixedVideoExitFullScreen:
-        return "'HTMLVideoElement.webkitExitFullScreen()' is deprecated. Please use 'Document.exitFullscreen()' and 'Document.webkitExitFullscreen()' instead.";
-
     case PrefixedMediaSourceOpen:
         return "'WebKitMediaSource' is deprecated. Please use 'MediaSource' instead.";