Add missing remoting tests to gn build

remoting/test/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.
 
 source_set("test_support") {
   testonly = true
 
   sources = [
     "access_token_fetcher.cc",
     "access_token_fetcher.h",
@@ skipping 72 matching lines @@
     "//testing/gtest",
     "//third_party/libjingle",
   ]
 }
 
 executable("chromoting_test_driver") {
   testonly = true
 
   sources = [
     "chromoting_test_driver.cc",
+    "chromoting_test_driver_tests.cc",
+    "chromoting_test_fixture.cc",
+    "chromoting_test_fixture.h",
   ]
 
   deps = [
     ":test_support",
     "//base/test:test_support",
     "//build/config/sanitizers:deps",
     "//build/win:default_exe_manifest",
     "//testing/gtest",
   ]
 }
@@ skipping 56 matching lines @@
     ":ar_test_driver_common",
     ":test_support",
     "//base",
     "//net:test_support",
     "//testing/gmock",
     "//testing/gtest",
     "//third_party/libyuv",
     "//third_party/webrtc/modules/desktop_capture",
   ]
 }