On windows filepaths need \\?\ prefix to allow extended file path names. Fix to bug 63574.

BUG=63574
TEST=file_system_operation_unittest.cc and manually tested on FAT32.


Review URL: http://codereview.chromium.org/5259003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@67385 0039d316-1c4b-4281-b951-d872f2087c98
5 files changed