dwmapi: Add DwmEnableMMCSS stub.

dlls/dwmapi/dwmapi.spec

@@ -24,7 +24,7 @@
 @ stub DwmDefWindowProc
 @ stub DwmDetachMilContent
 @ stub DwmEnableBlurBehindWindow
-@ stub DwmEnableMMCSS
+@ stdcall DwmEnableMMCSS(long)
 @ stdcall DwmExtendFrameIntoClientArea(long ptr)
 @ stdcall DwmFlush()
 @ stdcall DwmGetColorizationColor(ptr long)

dlls/dwmapi/dwmapi_main.c

@@ -119,3 +119,13 @@ HRESULT WINAPI DwmUnregisterThumbnail(HTHUMBNAIL thumbnail)
 
     return E_NOTIMPL;
 }
+
+/**********************************************************************
+ *           DwmEnableMMCSS         (DWMAPI.@)
+ */
+HRESULT WINAPI DwmEnableMMCSS(BOOL enableMMCSS)
+{
+    FIXME("(%d) stub\n", enableMMCSS);
+
+    return S_OK;
+}

include/dwmapi.h

@@ -32,6 +32,7 @@ extern "C" {
 DECLARE_HANDLE(HTHUMBNAIL);
 
 DWMAPI DwmEnableComposition(UINT);
+DWMAPI DwmEnableMMCSS(BOOL);
 DWMAPI DwmExtendFrameIntoClientArea(HWND,const MARGINS*);
 DWMAPI DwmGetColorizationColor(DWORD*,BOOL);
 DWMAPI DwmIsCompositionEnabled(BOOL*);