Coverity: Fix several pass-by-values.

sandbox/win/src/process_thread_dispatcher.cc

 // Copyright (c) 2006-2010 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 "sandbox/win/src/process_thread_dispatcher.h"
 
 #include "base/basictypes.h"
 #include "base/logging.h"
 #include "sandbox/win/src/crosscall_client.h"
 #include "sandbox/win/src/interception.h"
@@ skipping 46 matching lines @@
 // absolute.
 bool IsPathRelative(const std::wstring &path) {
   // A path is Relative if it's not a UNC path beginnning with \\ or a
   // path beginning with a drive. (i.e. X:\)
   if (path.find(L"\\\\") == 0 || path.find(L":\\") == 1)
     return false;
   return true;
 }
 
 // Converts a relative path to an absolute path.
-bool ConvertToAbsolutePath(const std::wstring child_current_directory,
+bool ConvertToAbsolutePath(const std::wstring& child_current_directory,
                            bool use_env_path, std::wstring *path) {
   wchar_t file_buffer[MAX_PATH];
   wchar_t *file_part = NULL;
 
   // Here we should start by looking at the path where the child application was
   // started. We don't have this information yet.
   DWORD result = 0;
   if (use_env_path) {
     // Try with the complete path
     result = ::SearchPath(NULL, path->c_str(), NULL, MAX_PATH, file_buffer,
@@ skipping 158 matching lines @@
   // If our logic was wrong, at least we wont allow create a random process.
   DWORD ret = ProcessPolicy::CreateProcessWAction(eval, *ipc->client_info,
                                                   exe_name, *cmd_line,
                                                   proc_info);
 
   ipc->return_info.win32_result = ret;
   return true;
 }
 
 }  // namespace sandbox