WindowSurfaceGLX: set the border pixel attribute
WindowSurfaceGLX: set the border pixel attribute

This is so we can use a different visual depth than our parent window so
that we can create a subwindow whichever the parent's visual.

BUG=angleproject:892

Change-Id: I9bab676761b1f80fad1599adb8e97a3ec710f67f
Reviewed-on: https://chromium-review.googlesource.com/271425
Reviewed-by: Kenneth Russell <1ebccd90c2bc76de65b6f830f2128a91ed69fdfb@chromium.org>
Tested-by: Corentin Wallez <470c533e86f4f848c98c7e11fffc2d043494a401@chromium.org>

MSOpenTech/angle,ppy/angle,mlfarrell/angle,mybios/angle,vvuk/angle,ghostoy/angle,bsergean/angle,ppy/angle,larsbergstrom/angle,crezefire/angle,mikolalysenko/angle,ecoal95/angle,mlfarrell/angle,csa7mdm/angle,MSOpenTech/angle,ghostoy/angle,vvuk/angle,MSOpenTech/angle,ghostoy/angle,bsergean/angle,mikolalysenko/angle,domokit/waterfall,csa7mdm/angle,larsbergstrom/angle,bsergean/angle,mybios/angle,vvuk/angle,ecoal95/angle,ecoal95/angle,ppy/angle,MSOpenTech/angle,domokit/waterfall,csa7mdm/angle,larsbergstrom/angle,crezefire/angle,ppy/angle,larsbergstrom/angle,mlfarrell/angle,crezefire/angle,crezefire/angle,mikolalysenko/angle,mybios/angle,ecoal95/angle,ghostoy/angle,mikolalysenko/angle,bsergean/angle,vvuk/angle,csa7mdm/angle,mybios/angle,mlfarrell/angle,ecoal95/angle