Move more code to using FilePath.

base/path_service.h

 // Copyright (c) 2006-2008 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.
 
 #ifndef BASE_PATH_SERVICE_H__
 #define BASE_PATH_SERVICE_H__
 
 #include "build/build_config.h"
 #ifdef OS_WIN
 // TODO(erikkay): this should be removable, but because SetCurrentDirectory
@@ skipping 45 matching lines @@
   static bool SetCurrentDirectory(const std::wstring& current_directory);
 
   // To extend the set of supported keys, you can register a path provider,
   // which is just a function mirroring PathService::Get.  The ProviderFunc
   // returns false if it cannot provide a non-empty path for the given key.
   // Otherwise, true is returned.
   //
   // WARNING: This function could be called on any thread from which the
   // PathService is used, so a the ProviderFunc MUST BE THREADSAFE.
   //
-  typedef bool (*ProviderFunc)(int, std::wstring*);
+  typedef bool (*ProviderFunc)(int, FilePath*);
 
   // Call to register a path provider.  You must specify the range "[key_start,
   // key_end)" of supported path keys.
   static void RegisterProvider(ProviderFunc provider,
                                int key_start,
                                int key_end);
  private:
   static bool GetFromCache(int key, FilePath* path);
   static void AddToCache(int key, const FilePath& path);
   
 };
 
 #endif // BASE_PATH_SERVICE_H__