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

media/cast/test/utility/input_builder.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 "media/cast/test/utility/input_builder.h"
 
 #include <stdlib.h>
 #include <cstdio>
 
 #include "base/command_line.h"
@@ skipping 45 matching lines @@
   return input;
 }
 
 int InputBuilder::GetIntInput() const {
   std::string string_input = GetStringInput();
   int int_value;
   CHECK(base::StringToInt(string_input, &int_value));
   return int_value;
 }
 
-bool InputBuilder::ValidateInput(const std::string input) const {
+bool InputBuilder::ValidateInput(const std::string& input) const {
   // Check for a valid range.
   if (low_range_ == INT_MIN && high_range_ == INT_MAX)
     return true;
   int value;
   if (!base::StringToInt(input, &value))
     return false;
   return value >= low_range_ && value <= high_range_;
 }
 
 }  // namespace test
 }  // namespace cast
 }  // namespace media