Log First User Interaction in Page Load Metrics

chrome/browser/page_load_metrics/observers/from_gws_page_load_metrics_observer.h

Index: chrome/browser/page_load_metrics/observers/from_gws_page_load_metrics_observer.h
diff --git a/chrome/browser/page_load_metrics/observers/from_gws_page_load_metrics_observer.h b/chrome/browser/page_load_metrics/observers/from_gws_page_load_metrics_observer.h
index 94fc16dc255f5bf7135a097dba8247533f5bbd68..f0de3577e0cab8e910482c10ba7c62d8a06e0b5b 100644
--- a/chrome/browser/page_load_metrics/observers/from_gws_page_load_metrics_observer.h
+++ b/chrome/browser/page_load_metrics/observers/from_gws_page_load_metrics_observer.h
@@ -47,6 +47,12 @@ class FromGWSPageLoadMetricsLogger {
     navigation_initiated_via_link_ = navigation_initiated_via_link;
   }
 
+  void SetNavigationStart(const base::TimeTicks navigation_start) {
+    // Should be invoked at most once
+    DCHECK(navigation_start_.is_null());
+    navigation_start_ = navigation_start;
+  }
+
   // Invoked when metrics for the given page are complete.
   void OnComplete(const page_load_metrics::PageLoadTiming& timing,
                   const page_load_metrics::PageLoadExtraInfo& extra_info);
@@ -70,6 +76,7 @@ class FromGWSPageLoadMetricsLogger {
                     const page_load_metrics::PageLoadExtraInfo& extra_info);
   void OnParseStop(const page_load_metrics::PageLoadTiming& timing,
                    const page_load_metrics::PageLoadExtraInfo& extra_info);
+  void OnUserInput(const blink::WebInputEvent& event);
 
   // The methods below are public only for testing.
   static bool IsGoogleSearchHostname(base::StringPiece host);
@@ -102,6 +109,14 @@ class FromGWSPageLoadMetricsLogger {
   bool provisional_url_has_search_hostname_ = false;
   bool provisional_url_is_non_http_or_https_ = false;
 
+  // The state of if first paint is triggered.
+  bool first_paint_triggered_ = false;
+
+  base::TimeTicks navigation_start_;
+
+  // The time of first user interaction after paint from navigation start.
+  base::TimeDelta first_user_interaction_after_paint_;
+
   // Common helper for QueryContainsComponent and QueryContainsComponentPrefix.
   static bool QueryContainsComponentHelper(const base::StringPiece query,
                                            const base::StringPiece component,
@@ -149,6 +164,8 @@ class FromGWSPageLoadMetricsObserver
       const page_load_metrics::PageLoadTiming& timing,
       const page_load_metrics::PageLoadExtraInfo& extra_info) override;
 
+  void OnUserInput(const blink::WebInputEvent& event) override;
+
  private:
   FromGWSPageLoadMetricsLogger logger_;