Get depot_tools first.
mkdir new-project
cd new-project
git clone https://github.com/victorgomes/v8-gn-example.git
gclient config https://github.com/victorgomes/v8-gn-example.git --unmanaged
cd v8-gn-example
gclient sync
gn gen out/release
autoninja -C out/release hello-world
./out/release/hello-world