Map ENFILE error to FILE_ERROR_TOO_MANY_OPENED.

File::OSErrorToFileError() was only mapping EMFILE to
FILE_ERROR_TOO_MANY_OPENED. Mapping ENFILE is one less FILE_ERROR_FAILED
returned.

Will not fix issue 766896, but might produce better logs.

Bug: 766896
Change-Id: I2c2a0fafe15b0415da1c65cfe9b6f13cafe38206
Reviewed-on: https://chromium-review.googlesource.com/706545Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Chris Mumford <cmumford@chromium.org>
Cr-Commit-Position: refs/heads/master@{#509666}

base/files/file_posix.cc

@@ -410,6 +410,7 @@ File::Error File::OSErrorToFileError(int saved_errno) {
       return FILE_ERROR_IO;
     case ENOENT:
       return FILE_ERROR_NOT_FOUND;
+    case ENFILE:  // fallthrough
     case EMFILE:
       return FILE_ERROR_TOO_MANY_OPENED;
     case ENOMEM: