Remove chromeos/chromeos.gyp.

.gn

 # This file is used by the GN meta build system to find the root of the source
 # tree and to set startup options. For documentation on the values set in this
 # file, run "gn help dotfile" at the command line.
 
 import("//build/dotfile_settings.gni")
 
 # The location of the build configuration file.
 buildconfig = "//build/config/BUILDCONFIG.gn"
 
 # The secondary source root is a parallel directory tree where
@@ skipping 240 matching lines @@
 #      this situation much easier to create. if the build always lists the
 #      files and passes them to a script, it will always be correct.
 
 exec_script_whitelist =
     build_dotfile_settings.exec_script_whitelist + [
       # Whitelist entries for //build should go into
       # //build/dotfile_settings.gni instead, so that they can be shared
       # with other repos. The entries in this list should be only for files
       # in the Chromium repo outside of //build.
       "//build_overrides/build.gni",
-      "//chromeos/BUILD.gn",
 
       # TODO(dgn): Layer violation but breaks the build otherwise, see
       # https://crbug.com/474506.
       "//clank/java/BUILD.gn",
       "//clank/native/BUILD.gn",
 
       "//remoting/host/installer/linux/BUILD.gn",
       "//remoting/remoting_version.gni",
       "//remoting/host/installer/win/generate_clsids.gni",
 
       # TODO(dpranke): Get these from the appropriate repos instead.
       "//third_party/angle/BUILD.gn",
       "//third_party/angle/src/tests/BUILD.gn",
       "//third_party/angle/src/vulkan_support/BUILD.gn",
       "//third_party/catapult/tracing/BUILD.gn",
       "//third_party/google_input_tools/inputview.gni",
 
       # CLD2 should be removed soon, delete this when we do.
       "//third_party/cld_2/BUILD.gn",
       "//tools/grit/grit_rule.gni",
 
       # Not gypi-to-gn.
       "//google_apis/BUILD.gn",
       "//printing/BUILD.gn",
     ]