winemac: Make the swap interval a property of the window, not the context.

dlls/winemac.drv/macdrv.h

@@ -141,6 +141,7 @@ struct macdrv_win_data
     unsigned int        per_pixel_alpha : 1;    /* is window using per-pixel alpha? */
     unsigned int        minimized : 1;          /* is window minimized? */
     unsigned int        being_dragged : 1;      /* is window being dragged under Cocoa's control? */
+    unsigned int        swap_interval : 1;      /* GL swap interval for window */
     struct window_surface *surface;
     struct window_surface *unminimized_surface;
 };

dlls/winemac.drv/window.c

@@ -239,6 +239,7 @@ static struct macdrv_win_data *alloc_win_data(HWND hwnd)
     {
         data->hwnd = hwnd;
         data->color_key = CLR_INVALID;
+        data->swap_interval = 1;
         EnterCriticalSection(&win_data_section);
         if (!win_datas)
             win_datas = CFDictionaryCreateMutable(NULL, 0, NULL, NULL);