Cleanup: Pass std::string as const reference from chrome/

chrome/browser/chromeos/login/screens/hid_detection_screen.cc

 // Copyright 2014 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/chromeos/login/screens/hid_detection_screen.h"
 
 #include "base/bind.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 342 matching lines @@
     } else {
       editor.SetString(kContextKeyKeyboardState, kUSBConnectedState);
     }
   }
   editor.SetString(kContextKeyKeyboardDeviceName, keyboard_device_name_)
         .SetBoolean(
             kContextKeyContinueButtonEnabled,
             !(pointing_device_id_.empty() && keyboard_device_id_.empty()));
 }
 
-void HIDDetectionScreen::SetKeyboardDeviceName_(std::string name) {
-  if (!(keyboard_device_id_.empty()) && name.empty())
-    name = l10n_util::GetStringUTF8(IDS_HID_DETECTION_DEFAULT_KEYBOARD_NAME);
-  keyboard_device_name_ = name;
+void HIDDetectionScreen::SetKeyboardDeviceName_(const std::string& name) {
+  keyboard_device_name_ =
+      keyboard_device_id_.empty() || !name.empty()
+          ? name
+          : l10n_util::GetStringUTF8(IDS_HID_DETECTION_DEFAULT_KEYBOARD_NAME);
 }
 
 void HIDDetectionScreen::DeviceAdded(
     device::BluetoothAdapter* adapter, device::BluetoothDevice* device) {
   VLOG(1) << "BT input device added id = " << device->GetDeviceID() <<
       " name = " << device->GetName();
   TryPairingAsPointingDevice(device);
   TryPairingAsKeyboardDevice(device);
 }
 
@@ skipping 163 matching lines @@
 void HIDDetectionScreen::SetPoweredOffError() {
   LOG(ERROR) << "Failed to power off BT adapter";
 }
 
 void HIDDetectionScreen::FindDevicesError() {
   VLOG(1) << "Failed to start Bluetooth discovery.";
 }
 
 
 }  // namespace chromeos