comctl32: Remove THEMING_SetSubclassData(). It is not used anymore.

dlls/comctl32/comctl32.h

@@ -276,6 +276,5 @@ LONG MONTHCAL_CompareSystemTime(const SYSTEMTIME *first, const SYSTEMTIME *secon
 extern void THEMING_Initialize(void) DECLSPEC_HIDDEN;
 extern void THEMING_Uninitialize(void) DECLSPEC_HIDDEN;
 extern LRESULT THEMING_CallOriginalClass(HWND, UINT, WPARAM, LPARAM) DECLSPEC_HIDDEN;
-extern void THEMING_SetSubclassData(HWND, ULONG_PTR) DECLSPEC_HIDDEN;
 
 #endif  /* __WINE_COMCTL32_H */

dlls/comctl32/theming.c

@@ -167,13 +167,3 @@ LRESULT THEMING_CallOriginalClass (HWND wnd, UINT msg, WPARAM wParam, LPARAM lPa
     WNDPROC oldProc = originalProcs[subclass];
     return CallWindowProcW (oldProc, wnd, msg, wParam, lParam);
 }
-
-/***********************************************************************
- * THEMING_SetSubclassData
- *
- * Update the "refData" value of the subclassed window.
- */
-void THEMING_SetSubclassData (HWND wnd, ULONG_PTR refData)
-{
-    SetPropW (wnd, (LPCWSTR)MAKEINTATOM(atRefDataProp), (HANDLE)refData);
-}