Run load state update timer only when needed

content/browser/loader/resource_dispatcher_host_impl.h

Index: content/browser/loader/resource_dispatcher_host_impl.h
diff --git a/content/browser/loader/resource_dispatcher_host_impl.h b/content/browser/loader/resource_dispatcher_host_impl.h
index 87181a3854c6c3a4cf0af0def319239e3e8a6c22..5d76880776e87048fc76ef6facfc837b9270920a 100644
--- a/content/browser/loader/resource_dispatcher_host_impl.h
+++ b/content/browser/loader/resource_dispatcher_host_impl.h
@@ -494,6 +494,12 @@ class CONTENT_EXPORT ResourceDispatcherHostImpl
                                int child_id,
                                bool is_sync_load);
 
+  // Schedules UpdateLoadInfo() to be invoked after a delay (for coalescing).
+  // This is only necessary when a page is loading or if there is an upload in
+  // progress. We want to avoid repeatedly calling this when we have a "hanging
+  // get" request like when on a Google Docs document.
+  void ScheduleUpdateLoadInfo();
+
   LoaderMap pending_loaders_;
 
   // Collection of temp files downloaded for child processes via
@@ -505,9 +511,8 @@ class CONTENT_EXPORT ResourceDispatcherHostImpl
       RegisteredTempFiles;  // key is child process id
   RegisteredTempFiles registered_temp_files_;
 
-  // A timer that periodically calls UpdateLoadStates while pending_requests_
-  // is not empty.
-  scoped_ptr<base::RepeatingTimer<ResourceDispatcherHostImpl> >
+  // A timer for scheduling a call to UpdateLoadInfo after a delay.
+  scoped_ptr<base::OneShotTimer<ResourceDispatcherHostImpl> >
       update_load_states_timer_;
 
   // We own the save file manager.