Refactoring button field and its type

third_party/WebKit/Source/platform/scroll/ScrollbarTheme.cpp

 /*
  * Copyright (C) 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 179 matching lines @@
     DrawingRecorder recorder(context, displayItemClient, DisplayItem::ScrollbarCorner, cornerRect);
 #if OS(MACOSX)
     context.fillRect(cornerRect, Color::white);
 #else
     Platform::current()->themeEngine()->paint(context.canvas(), WebThemeEngine::PartScrollbarCorner, WebThemeEngine::StateNormal, WebRect(cornerRect), 0);
 #endif
 }
 
 bool ScrollbarTheme::shouldCenterOnThumb(const ScrollbarThemeClient& scrollbar, const PlatformMouseEvent& evt)
 {
-    return Platform::current()->scrollbarBehavior()->shouldCenterOnThumb(static_cast<WebScrollbarBehavior::Button>(evt.button()), evt.shiftKey(), evt.altKey());
+    return Platform::current()->scrollbarBehavior()->shouldCenterOnThumb(evt.pointerProperties().button, evt.shiftKey(), evt.altKey());
 }
 
 bool ScrollbarTheme::shouldSnapBackToDragOrigin(const ScrollbarThemeClient& scrollbar, const PlatformMouseEvent& evt)
 {
     IntPoint mousePosition = scrollbar.convertFromRootFrame(evt.position());
     mousePosition.move(scrollbar.x(), scrollbar.y());
     return Platform::current()->scrollbarBehavior()->shouldSnapBackToDragOrigin(mousePosition, trackRect(scrollbar), scrollbar.orientation() == HorizontalScrollbar);
 }
 
 int ScrollbarTheme::thumbPosition(const ScrollbarThemeClient& scrollbar, float scrollPosition)
@@ skipping 130 matching lines @@
         return DisplayItem::ScrollbarBackTrack;
     case ForwardTrackPart:
         return DisplayItem::ScrollbarForwardTrack;
     default:
         ASSERT_NOT_REACHED();
         return DisplayItem::ScrollbarBackTrack;
     }
 }
 
 } // namespace blink