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

chrome/browser/page_load_metrics/observers/resource_prefetch_predictor_page_load_metrics_observer.h

Index: chrome/browser/page_load_metrics/observers/resource_prefetch_predictor_page_load_metrics_observer.h
diff --git a/chrome/browser/page_load_metrics/observers/resource_prefetch_predictor_page_load_metrics_observer.h b/chrome/browser/page_load_metrics/observers/resource_prefetch_predictor_page_load_metrics_observer.h
index 121b0a895ef7fba0aa672f903bc05b7f9b042870..1ec4ca9ac05e0be6c631442a56906332144bbcea 100644
--- a/chrome/browser/page_load_metrics/observers/resource_prefetch_predictor_page_load_metrics_observer.h
+++ b/chrome/browser/page_load_metrics/observers/resource_prefetch_predictor_page_load_metrics_observer.h
@@ -13,6 +13,7 @@ class WebContents;
 
 namespace predictors {
 class ResourcePrefetchPredictor;
+class GlowplugCollector;
 }
 
 namespace internal {
@@ -36,6 +37,7 @@ class ResourcePrefetchPredictorPageLoadMetricsObserver
   // outlive this observer.
   explicit ResourcePrefetchPredictorPageLoadMetricsObserver(
       predictors::ResourcePrefetchPredictor* predictor,
+      predictors::GlowplugCollector* collector,
       content::WebContents* web_contents);
 
   ~ResourcePrefetchPredictorPageLoadMetricsObserver() override;
@@ -56,6 +58,7 @@ class ResourcePrefetchPredictorPageLoadMetricsObserver
 
  private:
   predictors::ResourcePrefetchPredictor* predictor_;

[alexilin, 2017/05/22 13:20:36]

note:
Pointer to ResourcePrefetchPredictor should gone after we finish StatsCollector
refactoring.

+  predictors::GlowplugCollector* collector_;
   content::WebContents* web_contents_;
   bool record_histograms_;