Not all system metrics are DPI-dependent

[gix]

The explanations and code make it look like using GetSystemMetricsForDpi is enough. But for whatever reasons not all metrics are DPI-dependent. Notably, SM_CXEDGE, SM_CXBORDER and SM_CXDRAG (and their Y equivalents) are never scaled.

[tringi]

Interesting. So GetSystemMetricsForDpi returns scaled value, but Windows uses non-scaled anyway? I'll investigate...