The files in this directory are generated by gen_xproto.py.  To regenerate these
files, add "regenerate_x11_protos=true" to your gn args, then run the following
(assuming your build directory is out/Release):

$ rm -f ui/gfx/x/generated_protos/*.h
$ rm -f ui/gfx/x/generated_protos/*.cc
$ ninja -C out/Release ui/gfx/x:gen_xprotos
$ cp out/Release/gen/ui/gfx/x/*.h ui/gfx/x/generated_protos/
$ cp out/Release/gen/ui/gfx/x/*.cc ui/gfx/x/generated_protos/
$ git cl format