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

chrome/browser/predictors/loading_predictor.cc

 // Copyright 2017 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.
 
 #include "chrome/browser/predictors/loading_predictor.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
+#include "chrome/browser/predictors/loading_data_collector.h"
 #include "chrome/browser/predictors/resource_prefetch_common.h"
 #include "chrome/browser/predictors/resource_prefetch_predictor.h"
 
 namespace predictors {
 
 using URLRequestSummary = ResourcePrefetchPredictor::URLRequestSummary;
 
 LoadingPredictor::LoadingPredictor(const LoadingPredictorConfig& config,
                                    Profile* profile)
     : config_(config),
       profile_(profile),
       resource_prefetch_predictor_(
-          base::MakeUnique<ResourcePrefetchPredictor>(config, profile)) {}
+          base::MakeUnique<ResourcePrefetchPredictor>(config, profile)),
+      loading_data_collector_(base::MakeUnique<LoadingDataCollector>(
+          resource_prefetch_predictor())) {}
 
 LoadingPredictor::~LoadingPredictor() = default;
 
 void LoadingPredictor::PrepareForPageLoad(const GURL& url, HintOrigin origin) {
   if (active_hints_.find(url) != active_hints_.end() ||
       !resource_prefetch_predictor_->IsUrlPrefetchable(url))
     return;
 
   // To report hint durations.
   active_hints_.emplace(url, base::TimeTicks::Now());
 
   if (config_.IsPrefetchingEnabledForOrigin(profile_, origin))
     resource_prefetch_predictor_->StartPrefetching(url);
 }
 
 void LoadingPredictor::CancelPageLoadHint(const GURL& url) {
   CancelActiveHint(active_hints_.find(url));
 }
 
 void LoadingPredictor::StartInitialization() {
   resource_prefetch_predictor_->StartInitialization();
 }
 
+LoadingDataCollector* LoadingPredictor::loading_data_collector() const {
+  return loading_data_collector_.get();
+}
+
 ResourcePrefetchPredictor* LoadingPredictor::resource_prefetch_predictor()
     const {
   return resource_prefetch_predictor_.get();
 }
 
 void LoadingPredictor::Shutdown() {
   resource_prefetch_predictor_->Shutdown();
 }
 
 void LoadingPredictor::OnMainFrameRequest(const URLRequestSummary& summary) {
@@ skipping 73 matching lines @@
       const GURL& initial_url = it->second;
       CancelActiveHint(active_hints_.find(initial_url));
       it = active_navigations_.erase(it);
     } else {
       ++it;
     }
   }
 }
 
 }  // namespace predictors