Place source URL of DownloadFile in extended attributes

content/browser/file_metadata_linux.h

Index: content/browser/file_metadata_linux.h
===================================================================
--- content/browser/file_metadata_linux.h	(revision 0)
+++ content/browser/file_metadata_linux.h	(revision 0)
@@ -0,0 +1,31 @@
+// 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.
+
+#ifndef CONTENT_BROWSER_FILE_METADATA_LINUX_H_
+#define CONTENT_BROWSER_FILE_METADATA_LINUX_H_
+
+#include "content/common/content_export.h"
+
+class FilePath;
+class GURL;
+
+namespace file_metadata {

[darin (slow to review), 2012/07/24 05:00:04]

nit: why is this in content/browser/ and not content/browser/download/?

nit: why the namespace?  namespaces are supposed to match directory names (note:
we have a lot of violations of this rule in the source tree).

[cristian.patrasciuc, 2012/07/24 11:20:42]

There is already an implementation for Mac OS, under
content/browser/file_metadata_mac.h/mm. I decided to put the linux
implementation in the same folder and to use the same namespace (i.e.
file_metadata). If it's required I can move them (both linux and mac
implementations) under content/browser/download in a separate CL. They are only
used in content/browser/download/base_file.cc so there should be no problem.

+
+// The source URL attribute is part of the XDG standard.
+// The referrer URL attribute is not part of the XDG standard,
+// but it is used to keep the naming consistent.
+// http://freedesktop.org/wiki/CommonExtendedAttributes
+const char kSourceURLAttrName[] = "user.xdg.origin.url";

[darin (slow to review), 2012/07/24 05:00:04]

nit: just declare these here, define them in the .cc file, and  export them
instead?  that way you don't end up duplicating these into each translation
unit.  sure, the linker will probably eliminate duplicate symbols, but why add
more work for the linker? :-)

[cristian.patrasciuc, 2012/07/24 11:20:42]

Done.

+const char kReferrerURLAttrName[] = "user.xdg.referrer.url";
+
+// Adds origin metadata to the file.
+// |source| should be the source URL for the download, and |referrer| should be
+// the URL the user initiated the download from.
+CONTENT_EXPORT void AddOriginMetadataToFile(const FilePath& file,
+                                            const GURL& source,
+                                            const GURL& referrer);
+
+}  // namespace file_metadata
+
+#endif  // CONTENT_BROWSER_FILE_METADATA_LINUX_H_