[Chromoting] Add GN build support for ar_sample_app target.

remoting/remoting_version.gni

 # Copyright 2014 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/chrome_build.gni")
 
 _version_py_abspath = "//build/util/version.py"
 _remoting_version_abspath = "//remoting/VERSION"
 _chrome_version_abspath = "//chrome/VERSION"
 if (is_chrome_branded) {
   _remoting_branding_abspath = "//remoting/branding_Chrome"
 } else {
   _remoting_branding_abspath = "//remoting/branding_Chromium"
 }
 
 # Set these files as being input dependencies to the scripts, so the build will
 # be re-run if the files change.
-_script_deps = [
+remoting_version_files = [
   _remoting_version_abspath,
   _chrome_version_abspath,
   _remoting_branding_abspath,
 ]
 
 _chrome_version_path = rebase_path(_chrome_version_abspath, root_build_dir)
 _remoting_version_path = rebase_path(_remoting_version_abspath, root_build_dir)
 _remoting_branding_path =
     rebase_path(_remoting_branding_abspath, root_build_dir)
 
 version_major = exec_script(_version_py_abspath,
                             [
                               "-f",
                               _chrome_version_path,
                               "-f",
                               _remoting_version_path,
                               "-t \"@MAJOR@\"",
                             ],
                             "value",
-                            _script_deps)
+                            remoting_version_files)
 
 version_minor = exec_script(_version_py_abspath,
                             [
                               "-f",
                               _remoting_version_path,
                               "-t \"@REMOTING_PATCH@\"",
                             ],
                             "value",
-                            _script_deps)
+                            remoting_version_files)
 
 version_short =
     "${version_major}.${version_minor}." + exec_script(_version_py_abspath,
                                                        [
                                                          "-f",
                                                          _chrome_version_path,
                                                          "-f",
                                                          _remoting_version_path,
                                                          "-t \"@BUILD@\"",
                                                        ],
                                                        "value",
-                                                       _script_deps)
+                                                       remoting_version_files)
 
 version_full = "${version_short}." + exec_script(_version_py_abspath,
                                                  [
                                                    "-f",
                                                    _chrome_version_path,
                                                    "-f",
                                                    _remoting_version_path,
                                                    "-t \"@PATCH@\"",
                                                  ],
                                                  "value",
-                                                 _script_deps)
+                                                 remoting_version_files)
 
 prefpane_bundle_name = exec_script(_version_py_abspath,
                                    [
                                      "-f",
                                      _remoting_branding_path,
                                      "-t \"@MAC_PREFPANE_BUNDLE_NAME@\"",
                                    ],
                                    "string",
-                                   _script_deps)
+                                   remoting_version_files)
 
 host_bundle_name = exec_script(_version_py_abspath,
                                [
                                  "-f",
                                  _remoting_branding_path,
                                  "-t \"@MAC_HOST_BUNDLE_NAME@\"",
                                ],
                                "string",
-                               _script_deps)
+                               remoting_version_files)