Add a declarative way in c/b/s/sync_prefs.cc to say which data types have prefs

chrome/browser/ui/webui/sync_setup_handler.cc

Index: chrome/browser/ui/webui/sync_setup_handler.cc
diff --git a/chrome/browser/ui/webui/sync_setup_handler.cc b/chrome/browser/ui/webui/sync_setup_handler.cc
index 76313c8c8f4d41351f4b1877f75223ecb106b29d..7c93a0b3f1a74f7e09de623949b29b10a24f5f7c 100644
--- a/chrome/browser/ui/webui/sync_setup_handler.cc
+++ b/chrome/browser/ui/webui/sync_setup_handler.cc
@@ -104,10 +104,8 @@ bool GetConfiguration(const std::string& json, SyncConfiguration* config) {
   bool sync_extensions;
   if (!result->GetBoolean("syncExtensions", &sync_extensions))
     return false;
-  if (sync_extensions) {
+  if (sync_extensions)
     config->data_types.Put(syncable::EXTENSIONS);
-    config->data_types.Put(syncable::EXTENSION_SETTINGS);
-  }
 
   bool sync_typed_urls;
   if (!result->GetBoolean("syncTypedUrls", &sync_typed_urls))
@@ -124,10 +122,8 @@ bool GetConfiguration(const std::string& json, SyncConfiguration* config) {
   bool sync_apps;
   if (!result->GetBoolean("syncApps", &sync_apps))
     return false;
-  if (sync_apps) {
+  if (sync_apps)
     config->data_types.Put(syncable::APPS);
-    config->data_types.Put(syncable::APP_SETTINGS);
-  }
 
   // Encryption settings.
   if (!result->GetBoolean("encryptAllData", &config->encrypt_all))