Disable "using base::FilePath" on Linux since it now compiles.

chrome/installer/util/create_reg_key_work_item.cc

 // Copyright (c) 2010 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 <shlwapi.h>
 
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/win/registry.h"
 #include "chrome/installer/util/create_reg_key_work_item.h"
 #include "chrome/installer/util/install_util.h"
 #include "chrome/installer/util/logging_installer.h"
 
 using base::win::RegKey;
 
 namespace {
 
 // TODO: refactor this because it is only used once.
 void UpOneDirectoryOrEmpty(std::wstring* dir) {
-  FilePath path = FilePath::FromWStringHack(*dir);
-  FilePath directory = path.DirName();
+  base::FilePath path = base::FilePath::FromWStringHack(*dir);
+  base::FilePath directory = path.DirName();
   // If there is no separator, we will get back kCurrentDirectory.
   // In this case, clear dir.
-  if (directory == path || directory.value() == FilePath::kCurrentDirectory)
+  if (directory == path || directory.value() ==
+      base::FilePath::kCurrentDirectory)
     dir->clear();
   else
     *dir = directory.value();
 }
 
 }  // namespace
 
 CreateRegKeyWorkItem::~CreateRegKeyWorkItem() {
 }
 
@@ skipping 79 matching lines @@
 
   do {
     key_list_.push_back(key_path);
     // This is pure string operation so it does not matter whether the
     // path is file path or registry path.
     UpOneDirectoryOrEmpty(&key_path);
   } while (!key_path.empty());
 
   return true;
 }