[Sync] Refactoring polling to be reliable.

sync/sessions/status_controller.cc

Index: sync/sessions/status_controller.cc
diff --git a/sync/sessions/status_controller.cc b/sync/sessions/status_controller.cc
index 4610a5150d05f41079f9df123b6ea8f1b99e1da4..acb7f733b03a017bfc884bda5ee9c23f2fc7035d 100644
--- a/sync/sessions/status_controller.cc
+++ b/sync/sessions/status_controller.cc
@@ -36,6 +36,10 @@ void StatusController::UpdateStartTime() {
   sync_start_time_ = base::Time::Now();
 }
 
+void StatusController::UpdatePollTime() {
+  poll_finish_time_ = base::Time::Now();
+}
+
 void StatusController::set_num_successful_bookmark_commits(int value) {
   model_neutral_.num_successful_bookmark_commits = value;
 }