Move modules-dependent Event code out of core.

Source/modules/gamepad/GamepadEvent.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef GamepadEvent_h
 #define GamepadEvent_h
 
-#include "core/events/Event.h"
+#include "modules/EventModules.h"
 #include "modules/gamepad/Gamepad.h"
 
 namespace WebCore {
 
 struct GamepadEventInit : public EventInit {
     GamepadEventInit();
 
     Member<Gamepad> gamepad;
 };
 
@@ skipping 23 matching lines @@
     GamepadEvent();
     GamepadEvent(const AtomicString& type, bool canBubble, bool cancelable, Gamepad*);
     GamepadEvent(const AtomicString&, const GamepadEventInit&);
 
     PersistentWillBeMember<Gamepad> m_gamepad;
 };
 
 } // namespace WebCore
 
 #endif // GamepadEvent_h