Add UseCounters for Element.webkitRequestFullscreen/webkitRequestFullScreen

Source/core/dom/Element.idl

Index: Source/core/dom/Element.idl
diff --git a/Source/core/dom/Element.idl b/Source/core/dom/Element.idl
index 8d08592e183c95e3f5d9317ece7d9736d5446227..8d45e7d091190b9db985bb3e510830088782610f 100644
--- a/Source/core/dom/Element.idl
+++ b/Source/core/dom/Element.idl
@@ -122,10 +122,10 @@
 
     // Mozilla version
     const unsigned short ALLOW_KEYBOARD_INPUT = 1;
-    [RuntimeEnabled=Fullscreen, PerWorldBindings, ActivityLogging=AccessForAllWorlds] void webkitRequestFullScreen([Default=Undefined] optional unsigned short flags);
+    [RuntimeEnabled=Fullscreen, PerWorldBindings, ActivityLogging=AccessForAllWorlds, MeasureAs=PrefixedElementRequestFullScreen] void webkitRequestFullScreen([Default=Undefined] optional unsigned short flags);
 
     // W3C version
-    [RuntimeEnabled=Fullscreen, PerWorldBindings, ActivityLogging=AccessForAllWorlds] void webkitRequestFullscreen();
+    [RuntimeEnabled=Fullscreen, PerWorldBindings, ActivityLogging=AccessForAllWorlds, MeasureAs=PrefixedElementRequestFullscreen] void webkitRequestFullscreen();
 
     void webkitRequestPointerLock();