Add utf_string_conversions to base namespace.

chrome/browser/download/download_extensions.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 <set>
 #include <string>
 
 #include "chrome/browser/download/download_extensions.h"
 
 #include "base/string_util.h"
@@ skipping 201 matching lines @@
 #endif
 };
 
 DownloadDangerLevel GetFileDangerLevel(const base::FilePath& path) {
   base::FilePath::StringType extension(path.Extension());
   if (extension.empty())
     return NotDangerous;
   if (!IsStringASCII(extension))
     return NotDangerous;
 #if defined(OS_WIN)
-  std::string ascii_extension = WideToASCII(extension);
+  std::string ascii_extension = base::WideToASCII(extension);
 #elif defined(OS_POSIX)
   std::string ascii_extension = extension;
 #endif
 
   // Strip out leading dot if it's still there
   if (ascii_extension[0] == base::FilePath::kExtensionSeparator)
     ascii_extension.erase(0, 1);
 
   for (size_t i = 0; i < arraysize(g_executables); ++i) {
     if (LowerCaseEqualsASCII(ascii_extension, g_executables[i].extension))
@@ skipping 30 matching lines @@
   for (size_t i = 0; i < arraysize(kExecutableBlackList); ++i) {
     if (net::MatchesMimeType(kExecutableBlackList[i], mime_type))
       return false;
   }
   // We consider only other application types to be executable.
   return net::MatchesMimeType("application/*", mime_type);
 }
 
 
 }  // namespace download_util