Coverity: Pass parameters by reference.

chrome/browser/sync/glue/autofill_profile_model_associator.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/sync/glue/autofill_profile_model_associator.h"
 
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/sync/profile_sync_service.h"
 #include "chrome/browser/webdata/web_database.h"
 
@@ skipping 333 matching lines @@
 void AutofillProfileModelAssociator::Disassociate(int64 sync_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::DB));
   SyncIdToAutofillMap::iterator iter = id_map_inverse_.find(sync_id);
   if (iter == id_map_inverse_.end())
     return;
   CHECK(id_map_.erase(iter->second));
   id_map_inverse_.erase(iter);
 }
 
 int64 AutofillProfileModelAssociator::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;
 }
 
 void AutofillProfileModelAssociator::AbortAssociation() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   AutoLock lock(abort_association_pending_lock_);
   abort_association_pending_ = true;
 }
 
 bool AutofillProfileModelAssociator::IsAbortPending() {
   AutoLock lock(abort_association_pending_lock_);
   return abort_association_pending_;
 }
 
 }  // namespace browser_sync