Add cloud_print to the GN build.

cloud_print/virtual_driver/win/port_monitor/BUILD.gn

+# Copyright 2015 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("//chrome/version.gni")
+
+# When cross-compiling a 64-bit driver for a 32-bit build, some things get name
+# mangled with this suffix.
+if (target_cpu == "x86" && current_cpu == "x64") {
+  arch_suffix = "64"
+} else {
+  arch_suffix = ""
+}
+
+shared_library("port_monitor") {
+  output_name = "gcp_portmon$arch_suffix"
+
+  sources = [
+    "port_monitor.def",
+    "port_monitor_dll.cc",
+  ]
+
+  deps = [
+    ":lib",
+    ":resources",
+    "//base",
+    "//chrome:version_header",
+    "//chrome/common:constants",
+  ]
+
+  libs = [ "userenv.lib" ]
+}
+
+source_set("lib") {
+  sources = [
+    "port_monitor.cc",
+    "port_monitor.h",
+  ]
+
+  deps = [
+    "//base",
+    "//chrome/common:constants",
+    "//chrome/installer/launcher_support",
+    "//cloud_print/virtual_driver/win",
+  ]
+}
+
+process_version("resources") {
+  template_file = chrome_version_rc_template
+  sources = [
+    "../gcp_portmon${arch_suffix}_dll.ver",
+  ]
+
+  # Note: target_gen_dir will be different for each toolchain so the output
+  # name doesn't need mangling.
+  output = "$target_gen_dir/gcp_portmon_dll.rc"
+}