Match whole path components in DevicePathToDriveLetterPath(). Add tests.

base/file_util.h

Index: base/file_util.h
diff --git a/base/file_util.h b/base/file_util.h
index 78827e986e6c5170b8d906476be19a1addddb837..24699f9b6550f2fa41d25c5aa879814a880bb68d 100644
--- a/base/file_util.h
+++ b/base/file_util.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.
 
@@ -42,8 +42,22 @@ namespace base {
 class Time;
 }
 
+#if defined (OS_WIN)
+namespace base {
+namespace win {
+class WinApiInterface;
+}
+}
+#endif  // defined (OS_WIN)
+
 namespace file_util {
 
+#if defined (OS_WIN)
+bool DevicePathToDriveLetterPath(base::win::WinApiInterface& win_api,

[rvargas (doing something else), 2012/01/11 22:26:26]

If we put it here so that it has to be accessed by the tests, it needs
documentation, and it has to be exported.

+                                 const FilePath& device_path,
+                                 FilePath* out_drive_letter_path);
+#endif
+
 //-----------------------------------------------------------------------------
 // Functions that operate purely on a path string w/o touching the filesystem: