Remove UnusedParam.h

Source/platform/scroll/ScrollbarThemeMacCommon.mm

 /*
  * Copyright (C) 2008, 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 29 matching lines @@
 #include "platform/scroll/ScrollbarThemeClient.h"
 #include "platform/scroll/ScrollbarThemeMacNonOverlayAPI.h"
 #include "platform/scroll/ScrollbarThemeMacOverlayAPI.h"
 #include "public/platform/mac/WebThemeEngine.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebRect.h"
 #include "skia/ext/skia_utils_mac.h"
 #include "wtf/HashSet.h"
 #include "wtf/StdLibExtras.h"
 #include "wtf/TemporaryChange.h"
-#include "wtf/UnusedParam.h"
 
 // FIXME: There are repainting problems due to Aqua scroll bar buttons' visual overflow.
 
 using namespace std;
 using namespace WebCore;
 
 @interface NSColor (WebNSColorDetails)
 + (NSImage *)_linenPatternImage;
 @end
 
@@ skipping 282 matching lines @@
         case ForwardButtonEndPart:
             return kThemeBottomOutsideArrowPressed;
         case ThumbPart:
             return kThemeThumbPressed;
         default:
             return 0;
     }
 }
 
 } // namespace WebCore