PrependWrapper is platform-specific, so it should take a platform string.

chrome/browser/utility_process_host.cc

 // Copyright (c) 2009 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/utility_process_host.h"
 
 #include "app/app_switches.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/message_loop.h"
@@ skipping 91 matching lines @@
     cmd_line->AppendSwitch(switches::kIssue35198ExtraLogging);
 
 #if defined(OS_POSIX)
   // TODO(port): Sandbox this on Linux.  Also, zygote this to work with
   // Linux updating.
   bool has_cmd_prefix = browser_command_line.HasSwitch(
       switches::kUtilityCmdPrefix);
   if (has_cmd_prefix) {
     // launch the utility child process with some prefix (usually "xterm -e gdb
     // --args").
-    cmd_line->PrependWrapper(browser_command_line.GetSwitchValue(
+    cmd_line->PrependWrapper(browser_command_line.GetSwitchValueNative(
         switches::kUtilityCmdPrefix));
   }
 
   cmd_line->AppendSwitchPath(switches::kUtilityProcessAllowedDir, exposed_dir);
 #endif
 
   Launch(
 #if defined(OS_WIN)
       exposed_dir,
 #elif defined(OS_POSIX)
@@ skipping 31 matching lines @@
     IPC_MESSAGE_HANDLER(UtilityHostMsg_ParseUpdateManifest_Succeeded,
                         Client::OnParseUpdateManifestSucceeded)
     IPC_MESSAGE_HANDLER(UtilityHostMsg_ParseUpdateManifest_Failed,
                         Client::OnParseUpdateManifestFailed)
     IPC_MESSAGE_HANDLER(UtilityHostMsg_DecodeImage_Succeeded,
                         Client::OnDecodeImageSucceeded)
     IPC_MESSAGE_HANDLER(UtilityHostMsg_DecodeImage_Failed,
                         Client::OnDecodeImageFailed)
   IPC_END_MESSAGE_MAP_EX()
 }