Cleanup: Pass std::string as const reference if possible

sync/test/engine/mock_connection_manager.h

 // Copyright (c) 2012 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.
 //
 // Mock ServerConnectionManager class for use in client unit tests.
 
 #ifndef SYNC_TEST_ENGINE_MOCK_CONNECTION_MANAGER_H_
 #define SYNC_TEST_ENGINE_MOCK_CONNECTION_MANAGER_H_
 
 #include <bitset>
@@ skipping 32 matching lines @@
                         const std::string& auth_token,
                         ScopedServerStatusWatcher* watcher) override;
 
   // Control of commit response.
   // NOTE: Commit callback is invoked only once then reset.
   void SetMidCommitCallback(const base::Closure& callback);
   void SetMidCommitObserver(MidCommitObserver* observer);
 
   // Set this if you want commit to perform commit time rename. Will request
   // that the client renames all commited entries, prepending this string.
-  void SetCommitTimeRename(std::string prepend);
+  void SetCommitTimeRename(const std::string& prepend);
 
   // Generic versions of AddUpdate functions. Tests using these function should
   // compile for both the int64 and string id based versions of the server.
   // The SyncEntity returned is only valid until the Sync is completed
   // (e.g. with SyncShare.) It allows to add further entity properties before
   // sync, using SetLastXXX() methods and/or GetMutableLastUpdate().
   sync_pb::SyncEntity* AddUpdateDirectory(
       syncable::Id id,
       syncable::Id parent_id,
-      std::string name,
+      const std::string& name,
       int64 version,
       int64 sync_ts,
-      std::string originator_cache_guid,
-      std::string originator_client_item_id);
-  sync_pb::SyncEntity* AddUpdateBookmark(syncable::Id id,
-                                         syncable::Id parent_id,
-                                         std::string name,
-                                         int64 version,
-                                         int64 sync_ts,
-                                         std::string originator_cache_guid,
-                                         std::string originator_client_item_id);
+      const std::string& originator_cache_guid,
+      const std::string& originator_client_item_id);
+  sync_pb::SyncEntity* AddUpdateBookmark(
+      syncable::Id id,
+      syncable::Id parent_id,
+      const std::string& name,
+      int64 version,
+      int64 sync_ts,
+      const std::string& originator_cache_guid,
+      const std::string& originator_client_item_id);
   // Versions of the AddUpdate functions that accept integer IDs.
   sync_pb::SyncEntity* AddUpdateDirectory(
       int id,
       int parent_id,
-      std::string name,
+      const std::string& name,
       int64 version,
       int64 sync_ts,
-      std::string originator_cache_guid,
-      std::string originator_client_item_id);
-  sync_pb::SyncEntity* AddUpdateBookmark(int id,
-                                         int parent_id,
-                                         std::string name,
-                                         int64 version,
-                                         int64 sync_ts,
-                                         std::string originator_cache_guid,
-                                         std::string originator_client_item_id);
+      const std::string& originator_cache_guid,
+      const std::string& originator_client_item_id);
+  sync_pb::SyncEntity* AddUpdateBookmark(
+      int id,
+      int parent_id,
+      const std::string& name,
+      int64 version,
+      int64 sync_ts,
+      const std::string& originator_cache_guid,
+      const std::string& originator_client_item_id);
   // New protocol versions of the AddUpdate functions.
   sync_pb::SyncEntity* AddUpdateDirectory(
-      std::string id,
-      std::string parent_id,
-      std::string name,
+      const std::string& id,
+      const std::string& parent_id,
+      const std::string& name,
       int64 version,
       int64 sync_ts,
-      std::string originator_cache_guid,
-      std::string originator_client_item_id);
-  sync_pb::SyncEntity* AddUpdateBookmark(std::string id,
-                                         std::string parent_id,
-                                         std::string name,
-                                         int64 version,
-                                         int64 sync_ts,
-                                         std::string originator_cache_guid,
-                                         std::string originator_client_item_id);
+      const std::string& originator_cache_guid,
+      const std::string& originator_client_item_id);
+  sync_pb::SyncEntity* AddUpdateBookmark(
+      const std::string& id,
+      const std::string& parent_id,
+      const std::string& name,
+      int64 version,
+      int64 sync_ts,
+      const std::string& originator_cache_guid,
+      const std::string& originator_client_item_id);
   // Versions of the AddUpdate function that accept specifics.
   sync_pb::SyncEntity* AddUpdateSpecifics(
       int id,
       int parent_id,
-      std::string name,
+      const std::string& name,
       int64 version,
       int64 sync_ts,
       bool is_dir,
       int64 position,
       const sync_pb::EntitySpecifics& specifics);
   sync_pb::SyncEntity* AddUpdateSpecifics(
       int id,
       int parent_id,
-      std::string name,
+      const std::string& name,
       int64 version,
       int64 sync_ts,
       bool is_dir,
       int64 position,
       const sync_pb::EntitySpecifics& specifics,
-      std::string originator_cache_guid,
-      std::string originator_client_item_id);
+      const std::string& originator_cache_guid,
+      const std::string& originator_client_item_id);
   sync_pb::SyncEntity* SetNigori(
       int id,
       int64 version,
       int64 sync_ts,
       const sync_pb::EntitySpecifics& specifics);
   // Unique client tag variant for adding items.
-  sync_pb::SyncEntity* AddUpdatePref(std::string id,
-                                     std::string parent_id,
-                                     std::string client_tag,
+  sync_pb::SyncEntity* AddUpdatePref(const std::string& id,
+                                     const std::string& parent_id,
+                                     const std::string& client_tag,
                                      int64 version,
                                      int64 sync_ts);
 
   // Find the last commit sent by the client, and replay it for the next get
   // updates command.  This can be used to simulate the GetUpdates that happens
   // immediately after a successful commit.
   sync_pb::SyncEntity* AddUpdateFromLastCommit();
 
   // Add a deleted item.  Deletion records typically contain no
   // additional information beyond the deletion, and no specifics.
@@ skipping 58 matching lines @@
     next_new_id_ = value;
   }
   void set_conflict_n_commits(int value) {
     conflict_n_commits_ = value;
   }
 
   void set_use_legacy_bookmarks_protocol(bool value) {
     use_legacy_bookmarks_protocol_ = value;
   }
 
-  void set_store_birthday(std::string new_birthday) {
+  void set_store_birthday(const std::string& new_birthday) {
     // Multiple threads can set store_birthday_ in our tests, need to lock it to
     // ensure atomic read/writes and avoid race conditions.
     base::AutoLock lock(store_birthday_lock_);
     store_birthday_ = new_birthday;
   }
 
   void set_partial_throttling(bool value) { partialThrottling_ = value; }
 
   // Retrieve the number of GetUpdates requests that the mock server has
   // seen since the last time this function was called.  Can be used to
@@ skipping 34 matching lines @@
 
   // Explicitly indicate that we will not be fetching some updates.
   void ClearUpdatesQueue() {
     update_queue_.clear();
   }
 
   // Locate the most recent update message for purpose of alteration.
   sync_pb::SyncEntity* GetMutableLastUpdate();
 
  private:
-  sync_pb::SyncEntity* AddUpdateFull(syncable::Id id, syncable::Id parentid,
-                                     std::string name, int64 version,
+  sync_pb::SyncEntity* AddUpdateFull(syncable::Id id,
+                                     syncable::Id parentid,
+                                     const std::string& name,
+                                     int64 version,
                                      int64 sync_ts,
                                      bool is_dir);
-  sync_pb::SyncEntity* AddUpdateFull(std::string id,
-                                     std::string parentid, std::string name,
-                                     int64 version, int64 sync_ts,
+  sync_pb::SyncEntity* AddUpdateFull(const std::string& id,
+                                     const std::string& parentid,
+                                     const std::string& name,
+                                     int64 version,
+                                     int64 sync_ts,
                                      bool is_dir);
-  sync_pb::SyncEntity* AddUpdateMeta(std::string id, std::string parentid,
-                                    std::string name, int64 version,
-                                    int64 sync_ts);
+  sync_pb::SyncEntity* AddUpdateMeta(const std::string& id,
+                                     const std::string& parentid,
+                                     const std::string& name,
+                                     int64 version,
+                                     int64 sync_ts);
 
   // Functions to handle the various types of server request.
   void ProcessGetUpdates(sync_pb::ClientToServerMessage* csm,
                          sync_pb::ClientToServerResponse* response);
   void ProcessCommit(sync_pb::ClientToServerMessage* csm,
                      sync_pb::ClientToServerResponse* response_buffer);
   void ProcessClearServerData(sync_pb::ClientToServerMessage* csm,
                               sync_pb::ClientToServerResponse* response);
   void AddDefaultBookmarkData(sync_pb::SyncEntity* entity, bool is_folder);
 
@@ skipping 117 matching lines @@
   std::string next_token_;
 
   std::vector<sync_pb::ClientToServerMessage> requests_;
 
   DISALLOW_COPY_AND_ASSIGN(MockConnectionManager);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_TEST_ENGINE_MOCK_CONNECTION_MANAGER_H_