[Chromecast] Use ScopedTemp[File|Dir] in tests.

chromecast/base/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")  # TODO layering violation!
 import("//chromecast/chromecast.gni")
 import("//testing/test.gni")
 
+# GYP target: chromecast.gyp:cast_base
 source_set("base") {
   sources = [
     "android/dumpstate_writer.cc",
     "android/dumpstate_writer.h",
     "android/system_time_change_notifier_android.cc",
     "android/system_time_change_notifier_android.h",
     "cast_paths.cc",
     "cast_paths.h",
     "cast_resource.cc",
     "cast_resource.h",
@@ skipping 21 matching lines @@
   public_deps = [
     "//chromecast/base/metrics",
     "//chromecast/public",
   ]
 
   deps = [
     "//base",
   ]
 }
 
+# GYP target: n/a
+source_set("test_support") {
+  sources = [
+    "scoped_temp_file.cc",
+    "scoped_temp_file.h",
+  ]
+
+  public_deps = [
+    ":base",
+    "//base",
+  ]
+}
+
+# GYP target: chromecast_tests.gypi:cast_base_unittests
 test("cast_base_unittests") {
   sources = [
     "device_capabilities_impl_unittest.cc",
     "error_codes_unittest.cc",
     "path_utils_unittest.cc",
     "process_utils_unittest.cc",
     "serializers_unittest.cc",
     "system_time_change_notifier_unittest.cc",
   ]
 
   deps = [
-    ":base",
-    "//base",
+    ":test_support",
     "//base/test:run_all_unittests",
     "//base/test:test_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }
 
 source_set("cast_sys_info") {
   sources = [
     "cast_sys_info_dummy.cc",
@@ skipping 24 matching lines @@
     "-e",
     "CAST_BUILD_INCREMENTAL=20150608.181153",
     "-e",
     "CAST_BUILD_RELEASE=1.15",
     "-e",
     "CAST_IS_DEBUG_BUILD=1",
     "-e",
     "CAST_PRODUCT_TYPE=0",
   ]
 }