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..5dfb5d2fb2e3105ad7a4419790c0df803aed1322 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
@@ -70,6 +70,8 @@ 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,
+                   base::TimeDelta time_to_input);
 
   // The methods below are public only for testing.
   static bool IsGoogleSearchHostname(base::StringPiece host);
@@ -102,6 +104,13 @@ 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;
+
+  // First user interaction time from navigation start. Only record when the
+  // interaction happens after first paint.
+  base::TimeDelta first_user_interaction_time_;

[Bryan McQuade, 2016/05/27 15:03:31]

let's call this first_user_interaction_after_paint_ to be clearer

+
   // Common helper for QueryContainsComponent and QueryContainsComponentPrefix.
   static bool QueryContainsComponentHelper(const base::StringPiece query,
                                            const base::StringPiece component,
@@ -149,6 +158,9 @@ class FromGWSPageLoadMetricsObserver
       const page_load_metrics::PageLoadTiming& timing,
       const page_load_metrics::PageLoadExtraInfo& extra_info) override;
 
+  void OnUserInput(const blink::WebInputEvent& event,
+                   base::TimeDelta time_to_input) override;
+
  private:
   FromGWSPageLoadMetricsLogger logger_;