File BUILD.gn of Package chromium
import("//build/toolchain/gcc_toolchain.gni")
gcc_toolchain("default") {
  cc = getenv("CC")
  cxx = getenv("CXX")
  ar = "ar"
  nm = "nm"
  ld = cxx
  extra_cflags = getenv("CFLAGS")
  extra_cppflags = getenv("CPPFLAGS")
  extra_cxxflags = getenv("CXXFLAGS")
  extra_ldflags = getenv("LDFLAGS")
  toolchain_args = {
    current_cpu = current_cpu
    current_os = current_os
  }
}