Make validate_framebuffer return a WebGLResult<()>
Make validate_framebuffer return a WebGLResult<()>

szeged/servo,nnethercote/servo,KiChjang/servo,pyfisch/servo,saneyuki/servo,sadmansk/servo,peterjoel/servo,peterjoel/servo,paulrouget/servo,splav/servo,peterjoel/servo,SimonSapin/servo,saneyuki/servo,emilio/servo,nnethercote/servo,pyfisch/servo,pyfisch/servo,splav/servo,KiChjang/servo,splav/servo,saneyuki/servo,notriddle/servo,notriddle/servo,emilio/servo,KiChjang/servo,DominoTree/servo,sadmansk/servo,nnethercote/servo,paulrouget/servo,splav/servo,DominoTree/servo,splav/servo,jimberlage/servo,notriddle/servo,larsbergstrom/servo,peterjoel/servo,pyfisch/servo,splav/servo,jimberlage/servo,szeged/servo,pyfisch/servo,szeged/servo,SimonSapin/servo,emilio/servo,paulrouget/servo,larsbergstrom/servo,sadmansk/servo,emilio/servo,paulrouget/servo,nnethercote/servo,nnethercote/servo,pyfisch/servo,splav/servo,DominoTree/servo,SimonSapin/servo,peterjoel/servo,nnethercote/servo,saneyuki/servo,sadmansk/servo,emilio/servo,larsbergstrom/servo,saneyuki/servo,jimberlage/servo,emilio/servo,KiChjang/servo,szeged/servo,jimberlage/servo,szeged/servo,saneyuki/servo,peterjoel/servo,pyfisch/servo,KiChjang/servo,notriddle/servo,KiChjang/servo,emilio/servo,larsbergstrom/servo,szeged/servo,emilio/servo,saneyuki/servo,larsbergstrom/servo,nnethercote/servo,sadmansk/servo,peterjoel/servo,paulrouget/servo,DominoTree/servo,larsbergstrom/servo,DominoTree/servo,DominoTree/servo,SimonSapin/servo,SimonSapin/servo,paulrouget/servo,SimonSapin/servo,splav/servo,splav/servo,larsbergstrom/servo,jimberlage/servo,DominoTree/servo,paulrouget/servo,jimberlage/servo,sadmansk/servo,notriddle/servo,larsbergstrom/servo,pyfisch/servo,nnethercote/servo,paulrouget/servo,szeged/servo,splav/servo,jimberlage/servo,paulrouget/servo,paulrouget/servo,notriddle/servo,emilio/servo,jimberlage/servo,emilio/servo,DominoTree/servo,szeged/servo,jimberlage/servo,notriddle/servo,larsbergstrom/servo,sadmansk/servo,SimonSapin/servo,SimonSapin/servo,KiChjang/servo,DominoTree/servo,szeged/servo,KiChjang/servo,larsbergstrom/servo,peterjoel/servo,saneyuki/servo,saneyuki/servo,nnethercote/servo,KiChjang/servo,pyfisch/servo,szeged/servo,KiChjang/servo,pyfisch/servo,DominoTree/servo,peterjoel/servo,notriddle/servo,notriddle/servo,notriddle/servo,peterjoel/servo,nnethercote/servo,saneyuki/servo,sadmansk/servo