Remove PlatformMouseEvent and use WebMouseEvent instead

third_party/WebKit/Source/platform/scroll/ScrollbarThemeMac.h

 /*
  * Copyright (C) 2008 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 71 matching lines @@
   void paintThumb(GraphicsContext&, const Scrollbar&, const IntRect&) override;
 
   float thumbOpacity(const ScrollbarThemeClient&) const override;
 
   static NSScrollerStyle recommendedScrollerStyle();
 
  protected:
   int maxOverlapBetweenPages() override { return 40; }
 
   bool shouldDragDocumentInsteadOfThumb(const ScrollbarThemeClient&,
-                                        const PlatformMouseEvent&) override;
+                                        const WebMouseEvent&) override;
   int scrollbarPartToHIPressedState(ScrollbarPart);
 
   virtual void updateButtonPlacement(WebScrollbarButtonsPlacement) {}
 
   IntRect trackRect(const ScrollbarThemeClient&,
                     bool painting = false) override;
   IntRect backButtonRect(const ScrollbarThemeClient&,
                          ScrollbarPart,
                          bool painting = false) override;
   IntRect forwardButtonRect(const ScrollbarThemeClient&,
                             ScrollbarPart,
                             bool painting = false) override;
 
   bool hasButtons(const ScrollbarThemeClient&) override { return false; }
   bool hasThumb(const ScrollbarThemeClient&) override;
 
   int minimumThumbLength(const ScrollbarThemeClient&) override;
 
   int tickmarkBorderWidth() override { return 1; }
 
   RefPtr<Pattern> m_overhangPattern;
 };
 }
 
 #endif  // ScrollbarThemeMac_h