Implement triple buffering to avoid processor stalls

If we run RenderPerfTest with 15000 3DSphere objects we are seeing lesser FPS compared to other 3D primitives like 3DBox or 3DCylinder

Metal(15000 objects):
3D Box : 11.377 FPS
3D Cylinder : 10.075 FPS
3D Sphere : 6.309 FPS

OpenGL(15000 objects):
3D Box : 19.09 FPS
3D Cylinder : 18.953 FPS
3D Sphere : 18.75 FPS

Metal numbers are overall lesser than OpenGL numbers but in case of Sphere difference is more.