Create LoadingDataCollector class and have observers rely on it instead of ResourcePrefetchPredictor

chrome/test/BUILD.gn

Index: chrome/test/BUILD.gn
diff --git a/chrome/test/BUILD.gn b/chrome/test/BUILD.gn
index 38063ac6c3bd299fcbaa06206c1303eb1a10eda5..f5cd21b50a1c8bafc314669b81a995185246e2d0 100644
--- a/chrome/test/BUILD.gn
+++ b/chrome/test/BUILD.gn
@@ -1362,9 +1362,9 @@ test("browser_tests") {
       "../browser/policy/policy_network_browsertest.cc",
       "../browser/policy/policy_prefs_browsertest.cc",
       "../browser/policy/policy_startup_browsertest.cc",
+      "../browser/predictors/loading_test_util.cc",
+      "../browser/predictors/loading_test_util.h",
       "../browser/predictors/resource_prefetch_predictor_browsertest.cc",
-      "../browser/predictors/resource_prefetch_predictor_test_util.cc",
-      "../browser/predictors/resource_prefetch_predictor_test_util.h",
       "../browser/prefetch/prefetch_browsertest.cc",
       "../browser/prefs/pref_functional_browsertest.cc",
       "../browser/prefs/pref_service_browsertest.cc",
@@ -3138,13 +3138,13 @@ test("unit_tests") {
     "../browser/page_load_metrics/observers/document_write_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/from_gws_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/google_captcha_observer_unittest.cc",
+    "../browser/page_load_metrics/observers/loading_predictor_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/lofi_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/media_page_load_metrics_observer_unittest.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/observers/previews_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/protocol_page_load_metrics_observer_unittest.cc",
-    "../browser/page_load_metrics/observers/resource_prefetch_predictor_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/resource_tracking_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/service_worker_page_load_metrics_observer_unittest.cc",
     "../browser/page_load_metrics/observers/subresource_filter_metrics_observer_unittest.cc",
@@ -3176,12 +3176,13 @@ test("unit_tests") {
     "../browser/policy/profile_policy_connector_unittest.cc",
     "../browser/predictors/autocomplete_action_predictor_table_unittest.cc",
     "../browser/predictors/autocomplete_action_predictor_unittest.cc",
+    "../browser/predictors/loading_data_collector_unittest.cc",
     "../browser/predictors/loading_predictor_unittest.cc",
     "../browser/predictors/loading_stats_collector_unittest.cc",
+    "../browser/predictors/loading_test_util.cc",
+    "../browser/predictors/loading_test_util.h",
     "../browser/predictors/resource_prefetch_common_unittest.cc",
     "../browser/predictors/resource_prefetch_predictor_tables_unittest.cc",
-    "../browser/predictors/resource_prefetch_predictor_test_util.cc",
-    "../browser/predictors/resource_prefetch_predictor_test_util.h",
     "../browser/predictors/resource_prefetch_predictor_unittest.cc",
     "../browser/predictors/resource_prefetcher_unittest.cc",
     "../browser/prefs/chrome_command_line_pref_store_proxy_unittest.cc",