Introduce use counters for Blink specific editing event usage

Source/core/events/EventTarget.cpp

Index: Source/core/events/EventTarget.cpp
diff --git a/Source/core/events/EventTarget.cpp b/Source/core/events/EventTarget.cpp
index 3f1b07283c7ce7667810b795c23d42d9ec96b560..2801c7c5e1c0e4c19e9ef8f5b26cc2ad904f3485 100644
--- a/Source/core/events/EventTarget.cpp
+++ b/Source/core/events/EventTarget.cpp
@@ -36,6 +36,7 @@
 #include "bindings/v8/ExceptionState.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/NoEventDispatchAssertion.h"
+#include "core/editing/Editor.h"
 #include "core/events/Event.h"
 #include "core/inspector/InspectorInstrumentation.h"
 #include "core/frame/DOMWindow.h"
@@ -277,6 +278,7 @@ bool EventTarget::fireEventListeners(Event* event)
         event->setType(unprefixedTypeName);
     }
 
+    Editor::countEvent(executionContext(), event);
     countLegacyEvents(legacyTypeName, listenersVector, legacyListenersVector);
     return !event->defaultPrevented();
 }