Remove apt_config_val from apt.include

Remove apt_config_val from apt.include

find_apt_sources() used to dump all variables in apt-config and grep
for the needed variables.  However, apt-config provides a 'shell' arg
for this purpose, so we use that instead.  Also remove the unused
APT_SOURCES variable.

BUG=663069
R=mmoss@chromium.org

Committed: https://crrev.com/902df7e81d1c9f04e1500dd0bce59647b08d6b85
Cr-Commit-Position: refs/heads/master@{#435763}

[Tom (Use chromium acct), 2016-12-01 22:37:16]

Description was changed from

==========
Remove apt_config_val from apt.include

find_apt_sources() used to dump all variables in apt-config and grep
for the needed variables.  However, apt-config provides a 'shell' arg
for this purpose, so we use that instead.  Also remove the unused
APT_SOURCES variable.

BUG=663069
R=mmoss@chromium.org
==========

to

==========
Remove apt_config_val from apt.include

find_apt_sources() used to dump all variables in apt-config and grep
for the needed variables.  However, apt-config provides a 'shell' arg
for this purpose, so we use that instead.  Also remove the unused
APT_SOURCES variable.

BUG=663069
R=mmoss@chromium.org
==========

[Tom (Use chromium acct), 2016-12-01 22:44:56]

The CQ bit was checked by thomasanderson@google.com to run a CQ dry run

[commit-bot: I haz the power, 2016-12-01 22:45:24]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-12-01 22:53:36]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-12-01 22:53:36]

Dry run: This issue passed the CQ dry run.

[Michael Moss, 2016-12-01 23:34:23]

LGTM. Thanks, I totally forgot to go back and update this after I did the
chromoting one.

[Tom (Use chromium acct), 2016-12-01 23:34:55]

The CQ bit was checked by thomasanderson@google.com

[commit-bot: I haz the power, 2016-12-01 23:35:17]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-12-01 23:41:12]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1480635295438940, "parent_rev":
"be23de339b86176a5c1bb634c72d7549724c0c59", "commit_rev":
"38f179591c7d7f82f41db14baebeafdd8657da74"}

[commit-bot: I haz the power, 2016-12-01 23:41:40]

Description was changed from

==========
Remove apt_config_val from apt.include

find_apt_sources() used to dump all variables in apt-config and grep
for the needed variables.  However, apt-config provides a 'shell' arg
for this purpose, so we use that instead.  Also remove the unused
APT_SOURCES variable.

BUG=663069
R=mmoss@chromium.org
==========

to

==========
Remove apt_config_val from apt.include

find_apt_sources() used to dump all variables in apt-config and grep
for the needed variables.  However, apt-config provides a 'shell' arg
for this purpose, so we use that instead.  Also remove the unused
APT_SOURCES variable.

BUG=663069
R=mmoss@chromium.org
==========

[commit-bot: I haz the power, 2016-12-01 23:41:41]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-12-01 23:44:37]

Description was changed from

==========
Remove apt_config_val from apt.include

find_apt_sources() used to dump all variables in apt-config and grep
for the needed variables.  However, apt-config provides a 'shell' arg
for this purpose, so we use that instead.  Also remove the unused
APT_SOURCES variable.

BUG=663069
R=mmoss@chromium.org
==========

to

==========
Remove apt_config_val from apt.include

find_apt_sources() used to dump all variables in apt-config and grep
for the needed variables.  However, apt-config provides a 'shell' arg
for this purpose, so we use that instead.  Also remove the unused
APT_SOURCES variable.

BUG=663069
R=mmoss@chromium.org

Committed: https://crrev.com/902df7e81d1c9f04e1500dd0bce59647b08d6b85
Cr-Commit-Position: refs/heads/master@{#435763}
==========

[commit-bot: I haz the power, 2016-12-01 23:44:38]

Patchset 1 (id:??) landed as
https://crrev.com/902df7e81d1c9f04e1500dd0bce59647b08d6b85
Cr-Commit-Position: refs/heads/master@{#435763}