Remove PlatformEvent it is no longer used.

third_party/WebKit/Source/core/page/DragController.cpp

 /*
  * Copyright (C) 2007, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Google Inc.
  *
  * 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
@@ skipping 107 matching lines @@
 }
 #endif  // DCHECK_IS_ON()
 
 static WebMouseEvent createMouseEvent(DragData* dragData) {
   WebMouseEvent result(
       WebInputEvent::MouseMove, WebFloatPoint(dragData->clientPosition().x(),
                                               dragData->clientPosition().y()),
       WebFloatPoint(dragData->globalPosition().x(),
                     dragData->globalPosition().y()),
       WebPointerProperties::Button::Left, 0,
-      static_cast<PlatformEvent::Modifiers>(dragData->modifiers()),
+      static_cast<WebInputEvent::Modifiers>(dragData->modifiers()),
       TimeTicks::Now().InSeconds());
   // TODO(dtapuska): Really we should chnage DragData to store the viewport
   // coordinates and scale.
   result.setFrameScale(1);
   return result;
 }
 
 static DataTransfer* createDraggingDataTransfer(DataTransferAccessPolicy policy,
                                                 DragData* dragData) {
   return DataTransfer::create(DataTransfer::DragAndDrop, policy,
@@ skipping 1078 matching lines @@
   // operationForDrag can be pulled into WebCore itself
   DCHECK(dragData);
   return dragData->containsURL() && !m_didInitiateDrag ? DragOperationCopy
                                                        : DragOperationNone;
 }
 
 bool DragController::isCopyKeyDown(DragData* dragData) {
   int modifiers = dragData->modifiers();
 
 #if OS(MACOSX)
-  return modifiers & PlatformEvent::AltKey;
+  return modifiers & WebInputEvent::AltKey;
 #else
-  return modifiers & PlatformEvent::CtrlKey;
+  return modifiers & WebInputEvent::ControlKey;
 #endif
 }
 
 DEFINE_TRACE(DragController) {
   visitor->trace(m_page);
   visitor->trace(m_documentUnderMouse);
   visitor->trace(m_dragInitiator);
   visitor->trace(m_fileInputElementUnderMouse);
 }
 
 }  // namespace blink