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 "chrome/browser/predictors/loading_data_collector.h"
 #include "chrome/browser/predictors/resource_prefetch_predictor.h"
 
 namespace predictors {
 
 LoadingPredictor::LoadingPredictor(const LoadingPredictorConfig& config,
                                    Profile* profile) {
   resource_prefetch_predictor_ =
       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) {
   resource_prefetch_predictor_->StartPrefetching(url, origin);
 }
 
 void LoadingPredictor::CancelPageLoadHint(const GURL& url) {
   resource_prefetch_predictor_->StopPrefetching(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();
 }
 
 }  // namespace predictors