[Lanai] Primitives rendered with metal on non-retina monitor are different as compared to OpenGL

Although the primitive rendering works with Metal on non-retina display (-Dsun.java2d.uiScale=1.0 on retina display), it is not exactly equal to what gets rendered with OpenGL pipeline.
OpenGL code does some pixel calculation adjustments with magic numbers for pixel alignment. We need to replicate it in metal code path.