[NTP Snippets] Cleanups from clang-tidy

components/ntp_snippets/ntp_snippets_database.cc

Index: components/ntp_snippets/ntp_snippets_database.cc
diff --git a/components/ntp_snippets/ntp_snippets_database.cc b/components/ntp_snippets/ntp_snippets_database.cc
index 547aaa16aa5749739bae34587e68fe95d628d8de..d1aba2c33645a71e66ec2c4905bf76d391565110 100644
--- a/components/ntp_snippets/ntp_snippets_database.cc
+++ b/components/ntp_snippets/ntp_snippets_database.cc
@@ -22,7 +22,7 @@ const char kImageDatabaseUMAClientName[] = "NTPSnippetImages";
 
 const char kSnippetDatabaseFolder[] = "snippets";
 const char kImageDatabaseFolder[] = "images";
-}
+}  // namespace
 
 namespace ntp_snippets {
 
@@ -47,7 +47,7 @@ NTPSnippetsDatabase::NTPSnippetsDatabase(
                                    weak_ptr_factory_.GetWeakPtr()));
 }
 
-NTPSnippetsDatabase::~NTPSnippetsDatabase() {}
+NTPSnippetsDatabase::~NTPSnippetsDatabase() = default;
 
 bool NTPSnippetsDatabase::IsInitialized() const {
   return !IsErrorState() && database_initialized_ &&