EGLWindow: specify the device type only on d3d platform
EGLWindow: specify the device type only on d3d platform

BUG=angleproject:892

Change-Id: I2dda3a8d15e58d15a401258a5a64c5783ea1a132
Reviewed-on: https://chromium-review.googlesource.com/269666
Reviewed-by: Jamie Madill <7e492b4f1c8458024932de3ba475cbf015424c30@chromium.org>
Reviewed-by: Geoff Lang <b6fc25fe0362055230985c05cbfa8adb741ccc0f@chromium.org>
Tested-by: Corentin Wallez <470c533e86f4f848c98c7e11fffc2d043494a401@chromium.org>

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