Add utf_string_conversions to base namespace.

chrome/browser/extensions/api/system_info_storage/storage_info_provider_win.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 "chrome/browser/extensions/api/system_info_storage/storage_info_provider.h"
 
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include <windows.h>
 
@@ skipping 29 matching lines @@
   DWORD string_length = GetLogicalDriveStrings(
       kMaxLogicalDriveString - 1, logical_drive_strings);
   DCHECK(string_length % 4 == 0);
   // No drive found, return false.
   if (string_length == 0)
     return false;
 
   // Iterate the drive string by 4 wchars each step
   for (unsigned int i = 0; i < string_length; i += 4) {
     linked_ptr<StorageUnitInfo> unit(new StorageUnitInfo());
-    if (QueryUnitInfo(WideToUTF8(&logical_drive_strings[i]), unit.get())) {
+    if (QueryUnitInfo(base::WideToUTF8(&logical_drive_strings[i]),
+                      unit.get())) {
       info->push_back(unit);
     }
   }
   return true;
 }
 
 bool StorageInfoProviderWin::QueryUnitInfo(const std::string& id,
                                            StorageUnitInfo* info) {
   DCHECK(info);
   string16 drive = UTF8ToUTF16(id);
@@ skipping 33 matching lines @@
 }
 
 }  // namespace
 
 // static
 StorageInfoProvider* StorageInfoProvider::Get() {
   return StorageInfoProvider::GetInstance<StorageInfoProviderWin>();
 }
 
 }  // namespace extensions