Add TestMockTimeTaskRunner in base/test.

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 60 matching lines @@
     "test_file_util.h",
     "test_file_util_android.cc",
     "test_file_util_linux.cc",
     "test_file_util_mac.cc",
     "test_file_util_posix.cc",
     "test_file_util_win.cc",
     "test_io_thread.cc",
     "test_io_thread.h",
     "test_listener_ios.h",
     "test_listener_ios.mm",
+    "test_mock_time_task_runner.cc",
+    "test_mock_time_task_runner.h",
     "test_pending_task.cc",
     "test_pending_task.h",
     "test_reg_util_win.cc",
     "test_reg_util_win.h",
     "test_shortcut_win.cc",
     "test_shortcut_win.h",
     "test_simple_task_runner.cc",
     "test_simple_task_runner.h",
     "test_suite.cc",
     "test_suite.h",
@@ skipping 77 matching lines @@
 }
 
 if (is_android) {
   generate_jni("base_unittests_jni_headers") {
     sources = [
       "android/java/src/org/chromium/base/ContentUriTestUtils.java",
     ]
     jni_package = "base"
   }
 }