Remove PlatformEvent it is no longer used.

third_party/WebKit/Source/core/events/GestureEvent.cpp

 /*
  * Copyright (C) 2012 Google 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:
  *  * Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  *  * Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 64 matching lines @@
 
 GestureEvent::GestureEvent(const AtomicString& eventType,
                            AbstractView* view,
                            const WebGestureEvent& event)
     : UIEventWithKeyState(
           eventType,
           true,
           true,
           view,
           0,
-          static_cast<PlatformEvent::Modifiers>(event.modifiers()),
+          static_cast<WebInputEvent::Modifiers>(event.modifiers()),
           TimeTicks::FromSeconds(event.timeStampSeconds()),
           nullptr),
       m_nativeEvent(event) {}
 
 const AtomicString& GestureEvent::interfaceName() const {
   // FIXME: when a GestureEvent.idl interface is defined, return the string
   // "GestureEvent".  Until that happens, do not advertise an interface that
   // does not exist, since it will trip up the bindings integrity checks.
   return UIEvent::interfaceName();
 }
 
 bool GestureEvent::isGestureEvent() const {
   return true;
 }
 
 DEFINE_TRACE(GestureEvent) {
   UIEvent::trace(visitor);
 }
 
 }  // namespace blink