Merge M51: Add base::IsOnNetworkDrive.

Merge M51: Add base::IsOnNetworkDrive.

BUG=572131, 606622
TEST=base_unittests
TEST=http://pastebin.com/raw/jNUNwiQe

Review URL: https://codereview.chromium.org/1892153003

Cr-Commit-Position: refs/heads/master@{#387981}
(cherry picked from commit 2396e07db179be4f5a22ab2acc1503d0cdb1e499)

Committed: https://chromium.googlesource.com/chromium/src/+/ff34c287f8e4dc409a55222875eb2a59af8a4a11

[Will Harris, 2016-04-26 01:54:59]

Description was changed from

==========
Merge M51: Add base::IsOnNetworkDrive.

BUG=572131
TEST=base_unittests
TEST=http://pastebin.com/raw/jNUNwiQe

Review URL: https://codereview.chromium.org/1892153003

Cr-Commit-Position: refs/heads/master@{#387981}
(cherry picked from commit 2396e07db179be4f5a22ab2acc1503d0cdb1e499)
==========

to

==========
Merge M51: Add base::IsOnNetworkDrive.

BUG=572131,606622
TEST=base_unittests
TEST=http://pastebin.com/raw/jNUNwiQe

Review URL: https://codereview.chromium.org/1892153003

Cr-Commit-Position: refs/heads/master@{#387981}
(cherry picked from commit 2396e07db179be4f5a22ab2acc1503d0cdb1e499)
==========

[Will Harris, 2016-04-26 01:58:22]

Description was changed from

==========
Merge M51: Add base::IsOnNetworkDrive.

BUG=572131,606622
TEST=base_unittests
TEST=http://pastebin.com/raw/jNUNwiQe

Review URL: https://codereview.chromium.org/1892153003

Cr-Commit-Position: refs/heads/master@{#387981}
(cherry picked from commit 2396e07db179be4f5a22ab2acc1503d0cdb1e499)
==========

to

==========
Merge M51: Add base::IsOnNetworkDrive.

BUG=572131,606622
TEST=base_unittests
TEST=http://pastebin.com/raw/jNUNwiQe

Review URL: https://codereview.chromium.org/1892153003

Cr-Commit-Position: refs/heads/master@{#387981}
(cherry picked from commit 2396e07db179be4f5a22ab2acc1503d0cdb1e499)

Committed:
https://chromium.googlesource.com/chromium/src/+/ff34c287f8e4dc409a55222875eb...
==========

[Will Harris, 2016-04-26 01:58:23]

Committed patchset #1 (id:1) manually as
ff34c287f8e4dc409a55222875eb2a59af8a4a11.