[NTP Snippets] Shut down the service on database failure

components/ntp_snippets/ntp_snippets_service.cc

Index: components/ntp_snippets/ntp_snippets_service.cc
diff --git a/components/ntp_snippets/ntp_snippets_service.cc b/components/ntp_snippets/ntp_snippets_service.cc
index bf55467f307a661ea0b5c57667e600a0080cc465..48b3f0b11128729b6bde2273f06ad6b2b9e3d658 100644
--- a/components/ntp_snippets/ntp_snippets_service.cc
+++ b/components/ntp_snippets/ntp_snippets_service.cc
@@ -203,7 +203,7 @@ NTPSnippetsService::NTPSnippetsService(
       image_decoder_(std::move(image_decoder)),
       database_(std::move(database)),
       fetch_after_load_(false) {
-  // TODO(dgn) should be removed after branch point (https:://crbug.com/617585).
+  // TODO(dgn) should be removed after branch point (https://crbug.com/617585).
   ClearDeprecatedPrefs();
 
   if (explicitly_disabled_) {
@@ -211,6 +211,14 @@ NTPSnippetsService::NTPSnippetsService(
     return;
   }
 
+  if (database_->IsErrorState()) {
+    EnterState(State::SHUT_DOWN);
+    return;
+  }
+
+  database_->SetErrorCallback(base::Bind(&NTPSnippetsService::OnDatabaseError,
+                                         base::Unretained(this)));
+
   // We transition to other states while finalizing the initialization, when the
   // database is done loading.
   database_->LoadSnippets(base::Bind(&NTPSnippetsService::OnDatabaseLoaded,
@@ -325,6 +333,9 @@ void NTPSnippetsService::ClearDiscardedSnippets() {
   if (!initialized())
     return;
 
+  if (discarded_snippets_.empty())
+    return;
+
   database_->DeleteSnippets(discarded_snippets_);
   discarded_snippets_.clear();
 }
@@ -422,6 +433,10 @@ void NTPSnippetsService::OnDatabaseLoaded(NTPSnippet::PtrVector snippets) {
   FinishInitialization();
 }
 
+void NTPSnippetsService::OnDatabaseError() {
+  EnterState(State::SHUT_DOWN);
+}
+
 void NTPSnippetsService::OnSuggestionsChanged(
     const SuggestionsProfile& suggestions) {
   DCHECK(initialized());