wgl: Implemente SwapLayerBuffers.

src/gallium/state_trackers/wgl/icd/stw_icd.c

@@ -583,7 +583,7 @@ DrvSwapLayerBuffers(
    if (DBG)
       debug_printf( "%s\n", __FUNCTION__ );
 
-   return FALSE;
+   return stw_swap_layer_buffers( hdc, fuPlanes );
 }
 
 BOOL APIENTRY

src/gallium/state_trackers/wgl/shared/stw_framebuffer.c

@@ -237,6 +237,18 @@ stw_swap_buffers(
 }
 
 
+BOOL
+stw_swap_layer_buffers(
+   HDC hdc,
+   UINT fuPlanes )
+{
+   if(fuPlanes & WGL_SWAP_MAIN_PLANE)
+      return stw_swap_buffers(hdc);
+
+   return FALSE;
+}
+
+
 boolean
 stw_framebuffer_init_thread(void)
 {

src/gallium/state_trackers/wgl/shared/stw_public.h

@@ -50,6 +50,9 @@ BOOL stw_make_current( HDC hdc, UINT_PTR hglrc );
 
 BOOL stw_swap_buffers( HDC hdc );
 
+BOOL
+stw_swap_layer_buffers( HDC hdc, UINT fuPlanes );
+
 PROC stw_get_proc_address( LPCSTR lpszProc );
 
 int stw_pixelformat_describe( HDC hdc,

src/gallium/state_trackers/wgl/wgl/stw_wgl.c

@@ -100,10 +100,7 @@ wglSwapLayerBuffers(
    HDC hdc,
    UINT fuPlanes )
 {
-   (void) hdc;
-   (void) fuPlanes;
-
-   return FALSE;
+   return stw_swap_layer_buffers( hdc, fuPlanes );
 }
 
 WINGDIAPI PROC APIENTRY