[Clean-up] Replace the final straggler use of MockTimeProvider with Clock.

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 18 matching lines @@
     "launcher/test_result.h",
     "launcher/test_results_tracker.cc",
     "launcher/test_results_tracker.h",
     "launcher/unit_test_launcher.cc",
     "launcher/unit_test_launcher.h",
     "launcher/unit_test_launcher_ios.cc",
     "mock_chrome_application_mac.h",
     "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",
@@ skipping 119 matching lines @@
 }
 
 if (is_android) {
   generate_jni("base_unittests_jni_headers") {
     sources = [
       "android/java/src/org/chromium/base/ContentUriTestUtils.java",
     ]
     jni_package = "base"
   }
 }