Add a GN flag for the Windows multi-dll build.

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
@@ skipping 62 matching lines @@
                                    _script_deps)
 
 host_bundle_name = exec_script(_version_py_abspath,
                                [
                                  "-f",
                                  _remoting_branding_path,
                                  "-t \"@MAC_HOST_BUNDLE_NAME@\"",
                                ],
                                "string",
                                _script_deps)