Fix name conflict with FileSystemType from winnt.h

Fix name conflict with FileSystemType from winnt.h

winnt.h has this enum in global scope:
  typedef enum _CM_SERVICE_NODE_TYPE {
    ...
    FileSystemType = SERVICE_FILE_SYSTEM_DRIVER,
    ...
  } SERVICE_NODE_TYPE;

Clang complains that references to FileSystemType are ambiguous.  It
suggests using 'enum FileSystemType' to resolve the ambiguity, but that
seems weird in C++.

Instead, I changed the uses in this file to fileapi::FileSystemType and
left a comment where the using decl would naturally go.

R=kinuko@chromium.org
BUG=82385
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=200813

[kinuko, 2013-05-17 02:11:32]

(+vandebo, tommycli)

Gush, thanks for catching this. We'll consider renaming the type name as well...
lgtm.

[Reid Kleckner, 2013-05-17 14:08:22]

Committed patchset #1 manually as r200813 (presubmit successful).