Remove GN GYP generator.

tools/gn/secondary/net/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("//tools/grit/grit_rule.gni")
 
 component("net") {
-  external = true
   sources = [
     "android/cert_verify_result_android.h",
     "android/cert_verify_result_android_list.h",
     "android/gurl_utils.cc",
     "android/gurl_utils.h",
     "android/keystore.cc",
     "android/keystore.h",
     "android/keystore_openssl.cc",
     "android/keystore_openssl.h",
     "android/net_jni_registrar.cc",
@@ skipping 1171 matching lines @@
     if (posix_avoid_mmap) {
       defines = [ "POSIX_AVOID_MMAP" ]
       sources -= [ "disk_cache/mapped_file_posix.cc" ]
     } else {  # !posix_avoid_mmap
       sources -= [ "disk_cache/mapped_file_avoid_mmap_posix.cc" ]
     }
   }
 }
 
 #grit("net_resources") {
-#  external = true
 #  source = "base/net_resources.grd"
 #}
 
 static_library("http_server") {
-  external = true
   sources = [
     "server/http_connection.cc",
     "server/http_connection.h",
     "server/http_server.cc",
     "server/http_server.h",
     "server/http_server_request_info.cc",
     "server/http_server_request_info.h",
     "server/http_server_response_info.cc",
     "server/http_server_response_info.h",
     "server/web_socket.cc",
     "server/web_socket.h",
   ]
   configs += [ "//build/config/compiler:wexit_time_destructors" ]
   deps = [
     ":net",
     "//base",
   ]
 }