predictors: Mark before_first_contentful_paint for resources fetched before fcp.

chrome/browser/page_load_metrics/observers/resource_prefetch_predictor_page_load_metrics_observer.h

 // 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.
 
 #ifndef CHROME_BROWSER_PAGE_LOAD_METRICS_OBSERVERS_RESOURCE_PREFETCH_PREDICTOR_PAGE_LOAD_METRICS_OBSERVER_H_
 #define CHROME_BROWSER_PAGE_LOAD_METRICS_OBSERVERS_RESOURCE_PREFETCH_PREDICTOR_PAGE_LOAD_METRICS_OBSERVER_H_
 
 #include "chrome/browser/page_load_metrics/page_load_metrics_observer.h"
+#include "chrome/browser/predictors/resource_prefetch_predictor.h"

[alexilin, 2017/03/17 14:46:46]

nit:
NavigationID is declared in resource_prefetch_common.h.
You could include resource_prefetch_common.h. for NavigationID. and keep forward
declaration for ResourcePrefetchPredictor.

[trevordixon, 2017/03/27 12:30:08]

Done.

 
 namespace content {
 class WebContents;
 }
 
-namespace predictors {
-class ResourcePrefetchPredictor;
-}
-
 namespace internal {
 
 extern const char kHistogramResourcePrefetchPredictorFirstContentfulPaint[];
 extern const char kHistogramResourcePrefetchPredictorFirstMeaningfulPaint[];
 
 }  // namespace internal
 
 // Observer responsible for recording page load metrics relevant to
 // ResourcePrefetchPredictor.
 class ResourcePrefetchPredictorPageLoadMetricsObserver
     : public page_load_metrics::PageLoadMetricsObserver {
  public:
   // Returns a ResourcePrefetchPredictorPageLoadMetricsObserver, or nullptr if
   // it is not needed.
   static std::unique_ptr<ResourcePrefetchPredictorPageLoadMetricsObserver>
   CreateIfNeeded(content::WebContents* web_contents);
 
   // Public for testing. Normally one should use CreateIfNeeded. Predictor must
   // outlive this observer.
   explicit ResourcePrefetchPredictorPageLoadMetricsObserver(
-      predictors::ResourcePrefetchPredictor* predictor);
+      predictors::ResourcePrefetchPredictor* predictor,
+      predictors::NavigationID navigation_id);
 
   ~ResourcePrefetchPredictorPageLoadMetricsObserver() override;
 
   // page_load_metrics::PageLoadMetricsObserver:
   ObservePolicy OnStart(content::NavigationHandle* navigation_handle,
                         const GURL& currently_commited_url,
                         bool started_in_foreground) override;
   ObservePolicy OnHidden(
       const page_load_metrics::PageLoadTiming& timing,
       const page_load_metrics::PageLoadExtraInfo& extra_info) override;
   void OnFirstContentfulPaint(
       const page_load_metrics::PageLoadTiming& timing,
       const page_load_metrics::PageLoadExtraInfo& extra_info) override;
   void OnFirstMeaningfulPaint(
       const page_load_metrics::PageLoadTiming& timing,
       const page_load_metrics::PageLoadExtraInfo& extra_info) override;
 
  private:
   predictors::ResourcePrefetchPredictor* predictor_;
 
+  predictors::NavigationID navigation_id_;
+
   DISALLOW_COPY_AND_ASSIGN(ResourcePrefetchPredictorPageLoadMetricsObserver);
 };
 
 #endif  // CHROME_BROWSER_PAGE_LOAD_METRICS_OBSERVERS_RESOURCE_PREFETCH_PREDICTOR_PAGE_LOAD_METRICS_OBSERVER_H_