Coverity: Pass parameters by reference.

chrome/browser/sync/glue/autofill_model_associator2.cc

Index: chrome/browser/sync/glue/autofill_model_associator2.cc
diff --git a/chrome/browser/sync/glue/autofill_model_associator2.cc b/chrome/browser/sync/glue/autofill_model_associator2.cc
index 52bddc67c60be87874f17b66318e02bb5e5e3aa1..28872df8a72ad6a7192b2983332c3ebfbe734e53 100644
--- a/chrome/browser/sync/glue/autofill_model_associator2.cc
+++ b/chrome/browser/sync/glue/autofill_model_associator2.cc
@@ -421,13 +421,13 @@ AutofillModelAssociator2::GetChromeNodeFromSyncId(int64 sync_id) {
 }
 
 bool AutofillModelAssociator2::InitSyncNodeFromChromeId(
-    std::string node_id,
+    const std::string& node_id,
     sync_api::BaseNode* sync_node) {
   return false;
 }
 
 int64 AutofillModelAssociator2::GetSyncIdFromChromeId(
-    const std::string autofill) {
+    const std::string& autofill) {
   AutofillToSyncIdMap::const_iterator iter = id_map_.find(autofill);
   return iter == id_map_.end() ? sync_api::kInvalidId : iter->second;
 }