Enumerate the return value of dispatchEvent so it is clear.

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

Index: third_party/WebKit/Source/core/events/KeyboardEvent.h
diff --git a/third_party/WebKit/Source/core/events/KeyboardEvent.h b/third_party/WebKit/Source/core/events/KeyboardEvent.h
index 6165c23382661acc3a8f4a3a5f0df7fae285ddf8..56541514f1844ddfab2b1fc147d08598aae349cf 100644
--- a/third_party/WebKit/Source/core/events/KeyboardEvent.h
+++ b/third_party/WebKit/Source/core/events/KeyboardEvent.h
@@ -25,7 +25,6 @@
 #define KeyboardEvent_h
 
 #include "core/CoreExport.h"
-#include "core/events/EventDispatchMediator.h"
 #include "core/events/KeyboardEventInit.h"
 #include "core/events/UIEventWithKeyState.h"
 
@@ -86,8 +85,6 @@ public:
     bool isKeyboardEvent() const override;
     int which() const override;
 
-    PassRefPtrWillBeRawPtr<EventDispatchMediator> createMediator() override;
-
     DECLARE_VIRTUAL_TRACE();
 
 private:
@@ -107,14 +104,6 @@ private:
     unsigned m_location;
 };
 
-class KeyboardEventDispatchMediator : public EventDispatchMediator {
-public:
-    static PassRefPtrWillBeRawPtr<KeyboardEventDispatchMediator> create(PassRefPtrWillBeRawPtr<KeyboardEvent>);
-private:
-    explicit KeyboardEventDispatchMediator(PassRefPtrWillBeRawPtr<KeyboardEvent>);
-    bool dispatchEvent(EventDispatcher&) const override;
-};
-
 DEFINE_EVENT_TYPE_CASTS(KeyboardEvent);
 
 } // namespace blink