Deprecate the allowfullscreen exemption for <video>

Source/core/dom/Fullscreen.cpp

Index: Source/core/dom/Fullscreen.cpp
diff --git a/Source/core/dom/Fullscreen.cpp b/Source/core/dom/Fullscreen.cpp
index 4a59655a5a8715c82810724412b401e3733a73ca..8bab9eddd3ffbbc4ad12edb08f92692f754b6cb0 100644
--- a/Source/core/dom/Fullscreen.cpp
+++ b/Source/core/dom/Fullscreen.cpp
@@ -78,7 +78,7 @@ static bool fullscreenElementReady(const Element& element, Fullscreen::RequestTy
     // |element|'s node document's fullscreen enabled flag is set.
     if (!fullscreenIsAllowedForAllOwners(element.document())) {
         if (requestType == Fullscreen::PrefixedVideoRequest)
-            UseCounter::count(element.document(), UseCounter::VideoFullscreenAllowedExemption);
+            UseCounter::countDeprecation(element.document(), UseCounter::VideoFullscreenAllowedExemption);
         else
             return false;
     }