Track input latency while starting a ServiceWorker for a navigation hint.

content/browser/service_worker/service_worker_context_wrapper.h

Index: content/browser/service_worker/service_worker_context_wrapper.h
diff --git a/content/browser/service_worker/service_worker_context_wrapper.h b/content/browser/service_worker/service_worker_context_wrapper.h
index 020fa67f21974447e43e043c6466dba21b66e5b0..12c8b7220cd833464c774c76357a7bb6408573c5 100644
--- a/content/browser/service_worker/service_worker_context_wrapper.h
+++ b/content/browser/service_worker/service_worker_context_wrapper.h
@@ -188,6 +188,9 @@ class CONTENT_EXPORT ServiceWorkerContextWrapper
   // Must be called from the IO thread.
   bool OriginHasForeignFetchRegistrations(const GURL& origin);
 
+  // Must be called from the UI thread.
+  bool IsRunningNavigationHintTask(int render_process_id) const;
+
  private:
   friend class BackgroundSyncManagerTest;
   friend class base::RefCountedThreadSafe<ServiceWorkerContextWrapper>;
@@ -249,6 +252,9 @@ class CONTENT_EXPORT ServiceWorkerContextWrapper
                                               int render_process_id,
                                               const ResultCallback& callback,
                                               ServiceWorkerStatusCode code);
+  void DidFinishNavigationHintTaskOnUI(int render_process_id,
+                                       const ResultCallback& callback,
+                                       bool result);
 
   // The core context is only for use on the IO thread.
   // Can be null before/during init, during/after shutdown, and after
@@ -270,6 +276,9 @@ class CONTENT_EXPORT ServiceWorkerContextWrapper
   // The ResourceContext associated with this context.
   ResourceContext* resource_context_;
 
+  // Must be touched on the UI thread.
+  std::map<int, int> navigation_hint_task_count_per_process_;
+
   DISALLOW_COPY_AND_ASSIGN(ServiceWorkerContextWrapper);
 };