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

chrome/browser/predictors/resource_prefetch_predictor_tab_helper.cc

Index: chrome/browser/predictors/resource_prefetch_predictor_tab_helper.cc
diff --git a/chrome/browser/predictors/resource_prefetch_predictor_tab_helper.cc b/chrome/browser/predictors/resource_prefetch_predictor_tab_helper.cc
index 3b9a1fda5dfad3a01c1b75def0ecb8f0fff82e58..422b968c013bef8e0404a8eeff8fb64ddc57db73 100644
--- a/chrome/browser/predictors/resource_prefetch_predictor_tab_helper.cc
+++ b/chrome/browser/predictors/resource_prefetch_predictor_tab_helper.cc
@@ -34,10 +34,9 @@ void ResourcePrefetchPredictorTabHelper::DocumentOnLoadCompletedInMainFrame() {
   if (!loading_predictor)
     return;
 
-  auto* resource_prefetch_predictor =
-      loading_predictor->resource_prefetch_predictor();
+  auto* collector = loading_predictor->glowplug_collector();
   NavigationID navigation_id(web_contents());
-  resource_prefetch_predictor->RecordMainFrameLoadComplete(navigation_id);
+  collector->RecordMainFrameLoadComplete(navigation_id);
 }
 
 void ResourcePrefetchPredictorTabHelper::DidLoadResourceFromMemoryCache(
@@ -59,9 +58,8 @@ void ResourcePrefetchPredictorTabHelper::DidLoadResourceFromMemoryCache(
       ResourcePrefetchPredictor::GetResourceTypeFromMimeType(
           mime_type, resource_type);
   summary.was_cached = true;
-  auto* resource_prefetch_predictor =
-      loading_predictor->resource_prefetch_predictor();
-  resource_prefetch_predictor->RecordURLResponse(summary);
+  auto* collector = loading_predictor->glowplug_collector();
+  collector->RecordURLResponse(summary);
 }
 
 }  // namespace predictors