Fully qualify all references to fileapi::FileSystemType

Fully qualify all references to fileapi::FileSystemType

This avoids a name conflict between winnt.h's FileSystemType enumerator
value and Chromium's fileapi::FileSystemType enum type.  MSVC doesn't
care, but Clang diagnoses this with:
  error: must use 'enum' tag to refer to type 'FileSystemType' in this scope

I could use the enum tag to avoid this ambiguity, but it would be very
inconsistent with other Chromium code.  A full nested name specifier
seems better.

R=thakis@chromium.org,hans@chromium.org
TBR=kinuko@chromium.org
BUG=82385
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=278332

[hans, 2014-06-18 23:35:21]

lgtm

[Nico, 2014-06-18 23:39:31]

Prior art: https://codereview.chromium.org/14615015

kinuko said they're considering renaming their enum in that review; maybe it'll
happen some day :-)

lgtm

[Reid Kleckner, 2014-06-19 01:23:55]

Fix FileSystemType instances I missed

[Reid Kleckner, 2014-06-19 01:24:47]

The CQ bit was checked by rnk@chromium.org

[commit-bot: I haz the power, 2014-06-19 01:30:34]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/rnk@chromium.org/345673002/20001

[commit-bot: I haz the power, 2014-06-19 11:42:34]

Change committed as 278332