cc: Add HasPendingNotification to delayed unique notifier.

cc/base/delayed_unique_notifier.cc

Index: cc/base/delayed_unique_notifier.cc
diff --git a/cc/base/delayed_unique_notifier.cc b/cc/base/delayed_unique_notifier.cc
index 8086ba6538cd78fec0083edd6cd86a445806af39..c2972677da6fafcb2a4e4b935c4c8b5a0d7b179c 100644
--- a/cc/base/delayed_unique_notifier.cc
+++ b/cc/base/delayed_unique_notifier.cc
@@ -43,6 +43,10 @@ void DelayedUniqueNotifier::Cancel() {
   next_notification_time_ = base::TimeTicks();
 }
 
+bool DelayedUniqueNotifier::HasPendingNotification() const {
+  return notification_pending_ && !next_notification_time_.is_null();
+}
+
 base::TimeTicks DelayedUniqueNotifier::Now() const {
   return base::TimeTicks::Now();
 }