Clean up ifdef around FilePath creation(webkit)

net/base/mime_util.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 <algorithm>
 #include <iterator>
 #include <map>
 #include <string>
 
 #include "net/base/mime_util.h"
@@ skipping 201 matching lines @@
   const unsigned kMaxFilePathSize = 65536;
   if (ext.length() > kMaxFilePathSize)
     return false;
 
   // We implement the same algorithm as Mozilla for mapping a file extension to
   // a mime type.  That is, we first check a hard-coded list (that cannot be
   // overridden), and then if not found there, we defer to the system registry.
   // Finally, we scan a secondary hard-coded list to catch types that we can
   // deduce but that we also want to allow the OS to override.
 
-#if defined(OS_WIN)
-  string ext_narrow_str = WideToUTF8(ext);
-#elif defined(OS_POSIX)
-  const string& ext_narrow_str = ext;
-#endif
+  base::FilePath path_ext(ext);
+  const string ext_narrow_str = path_ext.AsUTF8Unsafe();
   const char* mime_type;
 
   mime_type = FindMimeType(primary_mappings, arraysize(primary_mappings),
                            ext_narrow_str.c_str());
   if (mime_type) {
     *result = mime_type;
     return true;
   }
 
   if (include_platform_types && GetPlatformMimeTypeFromExtension(ext, result))
@@ skipping 744 matching lines @@
   return CERTIFICATE_MIME_TYPE_UNKNOWN;
 }
 
 bool IsSupportedCertificateMimeType(const std::string& mime_type) {
   CertificateMimeType file_type =
       GetCertificateMimeTypeForMimeType(mime_type);
   return file_type != CERTIFICATE_MIME_TYPE_UNKNOWN;
 }
 
 }  // namespace net