Remove PlatformEvent it is no longer used.

third_party/WebKit/Source/core/input/EventHandler.h

 /*
  * Copyright (C) 2006, 2007, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 246 matching lines @@
   bool isTouchPointerIdActiveOnFrame(int, LocalFrame*) const;
 
  private:
   WebInputEventResult handleMouseMoveOrLeaveEvent(
       const WebMouseEvent&,
       const Vector<WebMouseEvent>&,
       HitTestResult* hoveredNode = nullptr,
       bool onlyUpdateScrollbars = false,
       bool forceLeave = false);
 
-  HitTestRequest::HitTestRequestType getHitTypeForGestureType(
-      PlatformEvent::EventType);
   void applyTouchAdjustment(WebGestureEvent*, HitTestResult*);
   WebInputEventResult handleGestureTapDown(
       const GestureEventWithHitTestResults&);
   WebInputEventResult handleGestureTap(const GestureEventWithHitTestResults&);
   WebInputEventResult handleGestureLongPress(
       const GestureEventWithHitTestResults&);
   WebInputEventResult handleGestureLongTap(
       const GestureEventWithHitTestResults&);
 
   void updateGestureTargetNodeForMouseEvent(
@@ skipping 107 matching lines @@
 
   // Set on GestureTapDown if the |pointerdown| event corresponding to the
   // triggering |touchstart| event was canceled. This suppresses mouse event
   // firing for the current gesture sequence (i.e. until next GestureTapDown).
   bool m_suppressMouseEventsFromGestures;
 };
 
 }  // namespace blink
 
 #endif  // EventHandler_h