predictors: Mark before_first_contentful_paint for resources fetched before fcp.

chrome/browser/predictors/resource_prefetch_predictor.h

Index: chrome/browser/predictors/resource_prefetch_predictor.h
diff --git a/chrome/browser/predictors/resource_prefetch_predictor.h b/chrome/browser/predictors/resource_prefetch_predictor.h
index cec2207d48f5d4d8e62642162e41a75cbbbdb7e7..c09b02433fcdfc3a3d3d29a3d7697264d6d2410a 100644
--- a/chrome/browser/predictors/resource_prefetch_predictor.h
+++ b/chrome/browser/predictors/resource_prefetch_predictor.h
@@ -114,6 +114,8 @@ class ResourcePrefetchPredictor
     GURL resource_url;
     content::ResourceType resource_type;
     net::RequestPriority priority;
+    base::TimeTicks response_time;
+    bool before_first_contentful_paint;
 
     // Only for responses.
     std::string mime_type;
@@ -138,6 +140,7 @@ class ResourcePrefetchPredictor
 
     GURL main_frame_url;
     GURL initial_url;
+    base::TimeTicks first_contentful_paint;
 
     // Stores all subresource requests within a single navigation, from initial
     // main frame request to navigation completion.
@@ -205,6 +208,11 @@ class ResourcePrefetchPredictor
   // Called when the main frame of a page completes loading.
   void RecordMainFrameLoadComplete(const NavigationID& navigation_id);
 
+  // Called after the main frame's first contentful paint.
+  void RecordFirstContentfulPaint(
+      const NavigationID& navigation_id,
+      const base::TimeTicks& first_contentful_paint);
+
   // Starts prefetching if it is enabled for |origin| and prefetching data
   // exists for the |main_frame_url| either at the URL or at the host level.
   void StartPrefetching(const GURL& main_frame_url, PrefetchOrigin origin);