It might be hard to explain just how unimportant this patch is. It is really a "nobody will notice", "no rush", "optional", "last-mile" kind of correction.
If you have a Blend file saved that includes windows on multiple monitors and those monitors differ in scale and/or dpi the placement of windows on some monitors can be out by a small amount.
The following capture illustrates the issue as it exists in master now. The right side is my middle (main) monitor with one window, and there is another window on the left monitor which is set to 150% scaling factor. I place the two windows as I want them (shown on the top), then "Save Startup File", close blender, then open again. The bottom of the capture shows how the left window has moved down a bit - an amount equal to the increased height of the titlebar.
After this patch is applied, both windows stick to their saved places exactly.
This is because when we want to place a window where we want we need to account for the space used by the window chrome. But it is only with Windows 10 that we can do this with accuracy in situations like this where the dpi and scale change.