As I commented in https://chromium-review.googlesource.com/c/chromiumos/platform/system_api/+/1006562, we want to categorize based on the source type (is it a removable drive, network filesystem, Google Drive, etc), rather than how we support them. If we end up supporting most of the new filesystems through the generic FUSE mechanism, the FUSE FS enum isn't very helpful

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/1fadef3c8995a037c76097d0440fec7db317c0d4

commit 1fadef3c8995a037c76097d0440fec7db317c0d4
Author: Sergei Datsenko <dats@chromium.org>
Date: Mon May 14 02:14:23 2018

cros-disks: Don't set "default" mount options.

Default parameters are determined by the CrosDisks, it's not up to
the client to decide which ones are the "default" so it ignores those
anyway.

BUG= chromium:831491 

Change-Id: Ibb8cc66b318282b15bfcb361a6428e37028dcf37
Reviewed-on: https://chromium-review.googlesource.com/1053343
Commit-Queue: Sergei Datsenko <dats@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Sam McNally <sammc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558174}
[modify] https://crrev.com/1fadef3c8995a037c76097d0440fec7db317c0d4/chromeos/dbus/cros_disks_client.cc
[modify] https://crrev.com/1fadef3c8995a037c76097d0440fec7db317c0d4/chromeos/dbus/cros_disks_client_unittest.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform2/+/da54a07076d4c0e7489aeb1ef252e6f97ad14687

commit da54a07076d4c0e7489aeb1ef252e6f97ad14687
Author: Sergei Datsenko <dats@google.com>
Date: Thu May 31 07:19:29 2018

cros-disks: Retry with 'ro' only physical media.

Move retrying a read-only mount if read-write failed to the disk mount manager
as it's not necessary relevant in general for non-physical media.

BUG= chromium:831491 
TEST=Unittests.

Change-Id: Iea7eb9810497f9f2baf9ecf75a9932948107f195
Reviewed-on: https://chromium-review.googlesource.com/1056652
Commit-Ready: Sergei Datsenko <dats@chromium.org>
Tested-by: Sergei Datsenko <dats@chromium.org>
Reviewed-by: Ben Chan <benchan@chromium.org>

[modify] https://crrev.com/da54a07076d4c0e7489aeb1ef252e6f97ad14687/cros-disks/mounter_unittest.cc
[modify] https://crrev.com/da54a07076d4c0e7489aeb1ef252e6f97ad14687/cros-disks/mounter.cc
[modify] https://crrev.com/da54a07076d4c0e7489aeb1ef252e6f97ad14687/cros-disks/drivefs_helper_unittest.cc
[modify] https://crrev.com/da54a07076d4c0e7489aeb1ef252e6f97ad14687/cros-disks/disk_manager.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform2/+/ac7a2641a21431df1d23c673847ebf15e6452f22

commit ac7a2641a21431df1d23c673847ebf15e6452f22
Author: Sergei Datsenko <dats@google.com>
Date: Thu Jul 26 09:08:13 2018

cros-disks: Retry with 'ro' only physical media.

Move retrying a read-only mount if read-write failed to the disk mount manager
as it's not necessary relevant in general for non-physical media.

BUG= chromium:831491 
TEST=Unittests.

Change-Id: Iea7eb9810497f9f2baf9ecf75a9932948107f195
Reviewed-on: https://chromium-review.googlesource.com/1056652
Commit-Ready: Sergei Datsenko <dats@chromium.org>
Tested-by: Sergei Datsenko <dats@chromium.org>
Reviewed-by: Ben Chan <benchan@chromium.org>
(cherry picked from commit da54a07076d4c0e7489aeb1ef252e6f97ad14687)
Reviewed-on: https://chromium-review.googlesource.com/1151127
Reviewed-by: Zhuohao Lee <zhuohao@chromium.org>
Commit-Queue: Zhuohao Lee <zhuohao@chromium.org>
Tested-by: Zhuohao Lee <zhuohao@chromium.org>

[modify] https://crrev.com/ac7a2641a21431df1d23c673847ebf15e6452f22/cros-disks/mounter_unittest.cc
[modify] https://crrev.com/ac7a2641a21431df1d23c673847ebf15e6452f22/cros-disks/mounter.cc
[modify] https://crrev.com/ac7a2641a21431df1d23c673847ebf15e6452f22/cros-disks/drivefs_helper_unittest.cc
[modify] https://crrev.com/ac7a2641a21431df1d23c673847ebf15e6452f22/cros-disks/disk_manager.cc