[NTP Snippets] Shut down the service on database failure

components/ntp_snippets/ntp_snippets_service.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/ntp_snippets/ntp_snippets_service.h"
 
 #include <algorithm>
 #include <iterator>
 #include <utility>
 
@@ skipping 185 matching lines @@
       sync_service_(sync_service),
       sync_service_observer_(this),
       suggestions_service_(suggestions_service),
       application_language_code_(application_language_code),
       scheduler_(scheduler),
       snippets_fetcher_(std::move(snippets_fetcher)),
       image_fetcher_(std::move(image_fetcher)),
       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_) {
     EnterState(State::DISABLED);
     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,
                                      base::Unretained(this)));
 }
 
 NTPSnippetsService::~NTPSnippetsService() {
   DCHECK(state_ == State::SHUT_DOWN);
 }
 
@@ skipping 94 matching lines @@
 
   FOR_EACH_OBSERVER(NTPSnippetsServiceObserver, observers_,
                     NTPSnippetsServiceLoaded());
   return true;
 }
 
 void NTPSnippetsService::ClearDiscardedSnippets() {
   if (!initialized())
     return;
 
+  if (discarded_snippets_.empty())
+    return;
+
   database_->DeleteSnippets(discarded_snippets_);
   discarded_snippets_.clear();
 }
 
 void NTPSnippetsService::AddObserver(NTPSnippetsServiceObserver* observer) {
   observers_.AddObserver(observer);
 }
 
 void NTPSnippetsService::RemoveObserver(NTPSnippetsServiceObserver* observer) {
   observers_.RemoveObserver(observer);
@@ skipping 77 matching lines @@
   std::sort(snippets_.begin(), snippets_.end(),
             [](const std::unique_ptr<NTPSnippet>& lhs,
                const std::unique_ptr<NTPSnippet>& rhs) {
               return lhs->score() > rhs->score();
             });
 
   ClearExpiredSnippets();
   FinishInitialization();
 }
 
+void NTPSnippetsService::OnDatabaseError() {
+  EnterState(State::SHUT_DOWN);
+}
+
 void NTPSnippetsService::OnSuggestionsChanged(
     const SuggestionsProfile& suggestions) {
   DCHECK(initialized());
 
   std::set<std::string> hosts = GetSuggestionsHostsImpl(suggestions);
   if (hosts == GetSnippetHostsFromPrefs())
     return;
 
   // Remove existing snippets that aren't in the suggestions anymore.
   // TODO(treib,maybelle): If there is another source with an allowed host,
@@ skipping 356 matching lines @@
       return;
   }
 }
 
 void NTPSnippetsService::ClearDeprecatedPrefs() {
   pref_service_->ClearPref(prefs::kDeprecatedSnippets);
   pref_service_->ClearPref(prefs::kDeprecatedDiscardedSnippets);
 }
 
 }  // namespace ntp_snippets