[Coverity] Fixed call by value to by reference

CID=102901

BUG=none
TEST=none


Review URL: http://codereview.chromium.org/9148018

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@117360 0039d316-1c4b-4281-b951-d872f2087c98


CrOS-Libchrome-Original-Commit: f5ae49373559c7492ec1e56dda6a5b270474c590
diff --git a/base/file_util_proxy.h b/base/file_util_proxy.h
index 1cde1ce..0b2cae5 100644
--- a/base/file_util_proxy.h
+++ b/base/file_util_proxy.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -41,7 +41,7 @@
                         bool /* created */)> CreateOrOpenCallback;
   typedef Callback<void(PlatformFileError,
                         PassPlatformFile,
-                        FilePath)> CreateTemporaryCallback;
+                        const FilePath&)> CreateTemporaryCallback;
   typedef Callback<void(PlatformFileError,
                         const PlatformFileInfo&
                        )> GetFileInfoCallback;