Add missing Display::getImplementation.
Add missing Display::getImplementation.

Change-Id: I220ffefcbf9bc988d986e729961c9a893d6b5159
Reviewed-on: https://chromium-review.googlesource.com/251580
Tested-by: Jamie Madill <7e492b4f1c8458024932de3ba475cbf015424c30@chromium.org>
Reviewed-by: Geoff Lang <b6fc25fe0362055230985c05cbfa8adb741ccc0f@chromium.org>

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