Add shutdown notification and service refs to SyncServiceObserver.

components/ntp_snippets/sessions/tab_delegate_sync_adapter.cc

Index: components/ntp_snippets/sessions/tab_delegate_sync_adapter.cc
diff --git a/components/ntp_snippets/sessions/tab_delegate_sync_adapter.cc b/components/ntp_snippets/sessions/tab_delegate_sync_adapter.cc
index 8f7733d919069cb593d27adc42c8e5e491bb656c..769a10ecb68e395be926a91f5d2075a5e150e46c 100644
--- a/components/ntp_snippets/sessions/tab_delegate_sync_adapter.cc
+++ b/components/ntp_snippets/sessions/tab_delegate_sync_adapter.cc
@@ -62,7 +62,8 @@ void TabDelegateSyncAdapter::OnStateChanged() {
   }
 }
 
-void TabDelegateSyncAdapter::OnSyncConfigurationCompleted() {
+void TabDelegateSyncAdapter::OnSyncConfigurationCompleted(
+    syncer::SyncService* sync) {
   // Ignored. This event can let us know when the set of enabled data types
   // change. However, we want to avoid useless notifications as much as
   // possible, and all of the information captured in this event will also be