scoped_refptr: support opaque pointed-to classes via extern template

base/test/BUILD.gn

 # Copyright (c) 2013 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/ui.gni")
 
 if (is_android) {
   import("//build/config/android/rules.gni")
 }
 
@@ skipping 23 matching lines @@
     "mock_chrome_application_mac.mm",
     "mock_devices_changed_observer.cc",
     "mock_devices_changed_observer.h",
     "mock_time_provider.cc",
     "mock_time_provider.h",
     "multiprocess_test.cc",
     "multiprocess_test.h",
     "multiprocess_test_android.cc",
     "null_task_runner.cc",
     "null_task_runner.h",
+    "opaque_ref_counted.cc",
+    "opaque_ref_counted.h",
     "perf_log.cc",
     "perf_log.h",
     "perf_test_suite.cc",
     "perf_test_suite.h",
     "perf_time_logger.cc",
     "perf_time_logger.h",
     "power_monitor_test_base.cc",
     "power_monitor_test_base.h",
     "scoped_locale.cc",
     "scoped_locale.h",
@@ skipping 110 matching lines @@
 }
 
 if (is_android) {
   generate_jni("base_unittests_jni_headers") {
     sources = [
       "android/java/src/org/chromium/base/ContentUriTestUtils.java",
     ]
     jni_package = "base"
   }
 }