Enumerate the return value of dispatchEvent so it is clear.

third_party/WebKit/Source/core/events/InputEvent.h

Index: third_party/WebKit/Source/core/events/InputEvent.h
diff --git a/third_party/WebKit/Source/core/events/InputEvent.h b/third_party/WebKit/Source/core/events/InputEvent.h
index 4cbffbea6e5fb1cc5211de8c26522eb5d3e277f1..f6c46ae58d23d1c655b4c72059353d8d97b9a273 100644
--- a/third_party/WebKit/Source/core/events/InputEvent.h
+++ b/third_party/WebKit/Source/core/events/InputEvent.h
@@ -26,8 +26,6 @@ public:
 
     bool isInputEvent() const override;
 
-    PassRefPtrWillBeRawPtr<EventDispatchMediator> createMediator() override;
-
     DECLARE_VIRTUAL_TRACE();
 
 private:
@@ -35,16 +33,6 @@ private:
     InputEvent(const AtomicString&, const InputEventInit&);
 };
 
-class InputEventDispatchMediator final : public EventDispatchMediator {
-public:
-    static PassRefPtrWillBeRawPtr<InputEventDispatchMediator> create(PassRefPtrWillBeRawPtr<InputEvent>);
-
-private:
-    explicit InputEventDispatchMediator(PassRefPtrWillBeRawPtr<InputEvent>);
-    InputEvent& event() const;
-    bool dispatchEvent(EventDispatcher&) const override;
-};
-
 DEFINE_EVENT_TYPE_CASTS(InputEvent);
 
 } // namespace blink