[NTP Snippets] Clear the snippets when the user signs out

chrome/browser/ui/webui/snippets_internals_message_handler.h

Index: chrome/browser/ui/webui/snippets_internals_message_handler.h
diff --git a/chrome/browser/ui/webui/snippets_internals_message_handler.h b/chrome/browser/ui/webui/snippets_internals_message_handler.h
index b45c30b62637a9098b220f967873ddbd548be259..bf1b4ad07c09cc62898afab43e313a9fe95bc473 100644
--- a/chrome/browser/ui/webui/snippets_internals_message_handler.h
+++ b/chrome/browser/ui/webui/snippets_internals_message_handler.h
@@ -34,6 +34,8 @@ class SnippetsInternalsMessageHandler
   void NTPSnippetsServiceLoaded() override;
   // Send when the service is shutting down.
   void NTPSnippetsServiceShutdown() override;
+  // Sent every time the service has its data sources cleared.
+  void NTPSnippetsServiceCleared() override;
 
   void HandleLoaded(const base::ListValue* args);
   void HandleClear(const base::ListValue* args);