style: Rename the PseudoId enum values to CamelCase and prefix them.

third_party/WebKit/Source/core/css/PseudoStyleRequest.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 42 matching lines @@
     }
 
     DEFINE_INLINE_TRACE()
     {
         visitor->trace(scrollbar);
     }
 
     // The spec disallows inheritance for ::backdrop.
     bool allowsInheritance(const ComputedStyle* parentStyle) const
     {
-        return parentStyle && pseudoId != BACKDROP;
+        return parentStyle && pseudoId != PseudoIdBackdrop;
     }
 
     PseudoId pseudoId;
     RequestType type;
     ScrollbarPart scrollbarPart;
     RawPtrWillBeMember<LayoutScrollbar> scrollbar;
 };
 
 } // namespace blink
 
 #endif // PseudoStyleRequest_h