Clear browsing data from ContentSuggestionService only if exists.

chrome/browser/ntp_snippets/content_suggestions_service_factory.cc

Index: chrome/browser/ntp_snippets/content_suggestions_service_factory.cc
diff --git a/chrome/browser/ntp_snippets/content_suggestions_service_factory.cc b/chrome/browser/ntp_snippets/content_suggestions_service_factory.cc
index 4d5f4e3f3588d829f234805cba2dc800e001be41..6ad50364d596ce40c765efd3d3d3ef6e888e3310 100644
--- a/chrome/browser/ntp_snippets/content_suggestions_service_factory.cc
+++ b/chrome/browser/ntp_snippets/content_suggestions_service_factory.cc
@@ -184,6 +184,13 @@ ContentSuggestionsService* ContentSuggestionsServiceFactory::GetForProfile(
       GetInstance()->GetServiceForBrowserContext(profile, true));
 }
 
+// static
+ContentSuggestionsService*
+ContentSuggestionsServiceFactory::GetForProfileIfExists(Profile* profile) {
+  return static_cast<ContentSuggestionsService*>(
+      GetInstance()->GetServiceForBrowserContext(profile, false));
+}
+
 ContentSuggestionsServiceFactory::ContentSuggestionsServiceFactory()
     : BrowserContextKeyedServiceFactory(
           "ContentSuggestionsService",