Reland: Buffer cross frame paint timing updates.

chrome/test/BUILD.gn

Index: chrome/test/BUILD.gn
diff --git a/chrome/test/BUILD.gn b/chrome/test/BUILD.gn
index 7f2ceae373795d33f95d79ba2f6dc98d17b03d60..a3b161f77863bfadd6517ab6a12940d95a28b0eb 100644
--- a/chrome/test/BUILD.gn
+++ b/chrome/test/BUILD.gn
@@ -1522,8 +1522,6 @@ test("browser_tests") {
       "../browser/ntp_snippets/content_suggestions_service_factory_browsertest.cc",
       "../browser/page_load_metrics/observers/ads_page_load_metrics_observer_browsertest.cc",
       "../browser/page_load_metrics/observers/https_engagement_metrics/https_engagement_page_load_metrics_observer_browsertest.cc",
-      "../browser/page_load_metrics/observers/page_load_metrics_observer_test_harness.cc",
-      "../browser/page_load_metrics/observers/page_load_metrics_observer_test_harness.h",
       "../browser/page_load_metrics/page_load_metrics_browsertest.cc",
       "../browser/password_manager/credential_manager_browsertest.cc",
       "../browser/password_manager/password_manager_browsertest.cc",
@@ -3325,6 +3323,8 @@ test("unit_tests") {
     "../common/media_router/media_source_helper_unittest.cc",
     "../common/media_router/media_source_unittest.cc",
     "../common/origin_trials/chrome_origin_trial_policy_unittest.cc",
+    "../common/page_load_metrics/test/weak_mock_timer.cc",
+    "../common/page_load_metrics/test/weak_mock_timer.h",
     "../common/partial_circular_buffer_unittest.cc",
     "../common/pref_names_util_unittest.cc",
     "../common/search/instant_types_unittest.cc",