[Extensions] Code cleanup - const &s

chrome/common/extensions/command_unittest.cc

 // 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.
 
 #include "chrome/common/extensions/command.h"
 
 #include <stddef.h>
 
 #include <memory>
 
@@ skipping 14 matching lines @@
   const char* command_name;
   const char* key;
   const char* description;
 } ConstCommandsTestData;
 
 // Checks the |suggested_key| value parses into a command when specified as a
 // string or dictionary of platform specific keys. If
 // |platform_specific_only| is true, only the latter is tested. |platforms|
 // specifies all platforms to use when populating the |suggested_key|
 // dictionary.
-void CheckParse(ConstCommandsTestData data,
+void CheckParse(const ConstCommandsTestData& data,
                 int i,
                 bool platform_specific_only,
                 std::vector<std::string>& platforms) {
   SCOPED_TRACE(std::string("Command name: |") + data.command_name + "| key: |" +
                data.key + "| description: |" + data.description + "| index: " +
                base::IntToString(i));
 
   extensions::Command command;
   std::unique_ptr<base::DictionaryValue> input(new base::DictionaryValue);
   base::string16 error;
@@ skipping 260 matching lines @@
   };
   std::vector<std::string> non_chromeos;
   non_chromeos.push_back("default");
   non_chromeos.push_back("windows");
   non_chromeos.push_back("mac");
   non_chromeos.push_back("linux");
 
   for (size_t i = 0; i < arraysize(kNonChromeOsSearchTests); ++i)
     CheckParse(kNonChromeOsSearchTests[i], i, true, non_chromeos);
 }