Virtualize EventDispatchMediator creation and cleanup calling.

Source/core/events/FocusEvent.h

Index: Source/core/events/FocusEvent.h
diff --git a/Source/core/events/FocusEvent.h b/Source/core/events/FocusEvent.h
index d59a7d83b4530c6e064dfc93e9f8be661bc4d08b..bcb1fd7d7768a748b30cfab02f91a3f4636734cd 100644
--- a/Source/core/events/FocusEvent.h
+++ b/Source/core/events/FocusEvent.h
@@ -56,6 +56,8 @@ public:
     const AtomicString& interfaceName() const override;
     bool isFocusEvent() const override;
 
+    PassRefPtrWillBeRawPtr<EventDispatchMediator> createMediator() override;
+
     DECLARE_VIRTUAL_TRACE();
 
 private:
@@ -77,33 +79,6 @@ private:
     bool dispatchEvent(EventDispatcher&) const override;
 };
 
-class BlurEventDispatchMediator final : public EventDispatchMediator {
-public:
-    static PassRefPtrWillBeRawPtr<BlurEventDispatchMediator> create(PassRefPtrWillBeRawPtr<FocusEvent>);
-private:
-    explicit BlurEventDispatchMediator(PassRefPtrWillBeRawPtr<FocusEvent>);
-    FocusEvent& event() const { return static_cast<FocusEvent&>(EventDispatchMediator::event()); }
-    bool dispatchEvent(EventDispatcher&) const override;
-};
-
-class FocusInEventDispatchMediator final : public EventDispatchMediator {
-public:
-    static PassRefPtrWillBeRawPtr<FocusInEventDispatchMediator> create(PassRefPtrWillBeRawPtr<FocusEvent>);
-private:
-    explicit FocusInEventDispatchMediator(PassRefPtrWillBeRawPtr<FocusEvent>);
-    FocusEvent& event() const { return static_cast<FocusEvent&>(EventDispatchMediator::event()); }
-    bool dispatchEvent(EventDispatcher&) const override;
-};
-
-class FocusOutEventDispatchMediator final : public EventDispatchMediator {
-public:
-    static PassRefPtrWillBeRawPtr<FocusOutEventDispatchMediator> create(PassRefPtrWillBeRawPtr<FocusEvent>);
-private:
-    explicit FocusOutEventDispatchMediator(PassRefPtrWillBeRawPtr<FocusEvent>);
-    FocusEvent& event() const { return static_cast<FocusEvent&>(EventDispatchMediator::event()); }
-    bool dispatchEvent(EventDispatcher&) const override;
-};
-
 } // namespace blink
 
 #endif // FocusEvent_h