Added wxWindow::ToDIP functionality.

src/common/wincmn.cpp

@@ -2878,6 +2878,18 @@ wxWindowBase::FromDIP(const wxSize& sz, const wxWindowBase* WXUNUSED(w))
                   sz.y == -1 ? -1 : wxMulDivInt32(sz.y, dpi.y, BASELINE_DPI));
 }
 
+/* static */
+wxSize
+wxWindowBase::ToDIP(const wxSize& sz, const wxWindowBase* WXUNUSED(w))
+{
+    const wxSize dpi = wxScreenDC().GetPPI();
+
+    // Take care to not scale -1 because it has a special meaning of
+    // "unspecified" which should be preserved.
+    return wxSize(sz.x == -1 ? -1 : wxMulDivInt32(sz.x, BASELINE_DPI, dpi.x),
+        sz.y == -1 ? -1 : wxMulDivInt32(sz.y, BASELINE_DPI, dpi.y));
+}
+
 #endif // !wxHAVE_DPI_INDEPENDENT_PIXELS
 
 // Windows' computes dialog units using average character width over upper-