Cleanup: Better constify some strings in chrome/browser/{chromeos,extensions}.

chrome/browser/extensions/activity_log/activity_database.cc

Index: chrome/browser/extensions/activity_log/activity_database.cc
diff --git a/chrome/browser/extensions/activity_log/activity_database.cc b/chrome/browser/extensions/activity_log/activity_database.cc
index 09b868be38f53b42173f96e305b82d80318226b3..286f24e4171dd2101a040b7384c55baca478ba47 100644
--- a/chrome/browser/extensions/activity_log/activity_database.cc
+++ b/chrome/browser/extensions/activity_log/activity_database.cc
@@ -202,8 +202,8 @@ void ActivityDatabase::SetTimerForTesting(int ms) {
 // static
 bool ActivityDatabase::InitializeTable(sql::Connection* db,
                                        const char* table_name,
-                                       const char* content_fields[],
-                                       const char* field_types[],
+                                       const char* const content_fields[],
+                                       const char* const field_types[],
                                        const int num_content_fields) {
   if (!db->DoesTableExist(table_name)) {
     std::string table_creator =