Move PathExists to base namespace.

chrome/browser/shell_integration_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/shell_integration.h"
 
 #include <windows.h>
 #include <shobjidl.h>
 #include <propkey.h>
 
@@ skipping 512 matching lines @@
   size_t folder =
       InstallUtil::IsPerUserInstall(chrome_exe.value().c_str()) ? 1 : 0;
   for (; folder < arraysize(kFolderIds); ++folder) {
     if (!PathService::Get(kFolderIds[folder], &shortcut)) {
       NOTREACHED();
       continue;
     }
 
     shortcut = shortcut.Append(shortcut_name).Append(shortcut_name +
                                                      installer::kLnkExt);
-    if (file_util::PathExists(shortcut))
+    if (base::PathExists(shortcut))
       return shortcut;
   }
 
   return base::FilePath();
 }