Remove GN GYP generator.

tools/gn/secondary/chrome/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/crypto.gni")
 import("//build/config/ui.gni")
 import("//tools/grit/grit_rule.gni")
 
 executable("chrome") {
   sources = [
@@ skipping 46 matching lines @@
 
   if (!is_win) {
     sources -= [
       "app/client_util.cc",
       "app/client_util.h",
     ]
   }
 }
 
 static_library("browser") {
-  external = true
-
   if (is_linux) {
     if (toolkit_uses_gtk) {
       libs = [ "gconf-2" ]
     }
   }
   if (is_linux) {
     configs += [
       "//build/config/linux:x11",
     ]
   }
 
   deps = [
     "//third_party/expat",
   ]
 }
 
 static_library("common") {
-  external = true
-
   if (use_nss && is_linux) {
     # common/net uses NSS.
     # TODO(brettw) have a better way to express this without having to do
     # "if (use_nss)" everywhere.
     configs += [ "//third_party/nss:nss_linux_config" ]
   }
   deps = [
   ]
 }
 
@@ skipping 65 matching lines @@
   # }
   # TODO(brettw) this may be required on Windows:
   # if (is_win) {
   #   TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
   #   'msvs_disabled_warnings': [ 4267, ]
   # }
 
 }
 
 source_set("plugin") {
-  external = true
 }
 
 source_set("renderer") {
-  external = true
 }
 
 source_set("utility") {
-  external = true
 }
 
 
 # Credits ----------------------------------------------------------------------
 
 about_credits_file = "$root_gen_dir/about_credits.html"
 build_relative_about_credits_file =
   rebase_path(about_credits_file, root_build_dir)
 
 custom("about_credits") {
@@ skipping 105 matching lines @@
 #    ":theme_resources_gen",
 #    #"//ui:ui_resources",
 #  ]
 #}
 #
 ## TODO(brettw) rename "app_theme_resources" or something when we don't support
 ## GYP any more. This name is required to match the GYP build.
 #grit("theme_resources_gen") {
 #  source = "app/theme/theme_resources.grd"
 #}