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

chrome/browser/BUILD.gn

Index: chrome/browser/BUILD.gn
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index 3dc58f0323b47b9a225cee733aa061ffb55741dc..19eac323d52760af67b366da179b41b4c91f47a2 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -840,6 +840,8 @@ split_static_library("browser") {
     "page_load_metrics/observers/https_engagement_metrics/https_engagement_service.h",
     "page_load_metrics/observers/https_engagement_metrics/https_engagement_service_factory.cc",
     "page_load_metrics/observers/https_engagement_metrics/https_engagement_service_factory.h",
+    "page_load_metrics/observers/loading_predictor_page_load_metrics_observer.cc",
+    "page_load_metrics/observers/loading_predictor_page_load_metrics_observer.h",
     "page_load_metrics/observers/lofi_page_load_metrics_observer.cc",
     "page_load_metrics/observers/lofi_page_load_metrics_observer.h",
     "page_load_metrics/observers/media_page_load_metrics_observer.cc",
@@ -854,8 +856,6 @@ split_static_library("browser") {
     "page_load_metrics/observers/previews_page_load_metrics_observer.h",
     "page_load_metrics/observers/protocol_page_load_metrics_observer.cc",
     "page_load_metrics/observers/protocol_page_load_metrics_observer.h",
-    "page_load_metrics/observers/resource_prefetch_predictor_page_load_metrics_observer.cc",
-    "page_load_metrics/observers/resource_prefetch_predictor_page_load_metrics_observer.h",
     "page_load_metrics/observers/resource_tracking_page_load_metrics_observer.cc",
     "page_load_metrics/observers/resource_tracking_page_load_metrics_observer.h",
     "page_load_metrics/observers/service_worker_page_load_metrics_observer.cc",
@@ -975,6 +975,8 @@ split_static_library("browser") {
     "predictors/glowplug_key_value_data.h",
     "predictors/glowplug_key_value_table.cc",
     "predictors/glowplug_key_value_table.h",
+    "predictors/loading_data_collector.cc",
+    "predictors/loading_data_collector.h",
     "predictors/loading_predictor.cc",
     "predictors/loading_predictor.h",
     "predictors/loading_predictor_android.cc",