There's no reason to do that. Firstly it's bound to only work on vga hardware, which noone uses in win xp anymore, and you should much rather use the inbuilt support for double buffering anyway.

Afaik, if you set OpenGL to use VSync any call to FlipBuffers should block until VSync, and in DirectX the same happens when you call Present

I don't know what you would use for other api's, but the most logic way to do it for them, would be to just block(eg. wait) until vsync