Revert of Simplify condition to use libc++

Revert of Simplify condition to use libc++ (patchset #2 id:20001 of https://codereview.chromium.org/2963183003/ )

Reason for revert:

Findit (https://goo.gl/kROfz5) identified CL at revision 483787 as the
culprit for failures in the build cycles as shown on:
https://findit-for-me.appspot.com/waterfall/culprit?key=ag9zfmZpbmRpdC1mb3ItbWVyRAsSDVdmU3VzcGVjdGVkQ0wiMWNocm9taXVtLzNiNTE1MjUzOGQxMzNmNTlhYTY3MDlhMDgxMWZmNmM3NDU5NzNjYzYM

Original issue's description:
> Simplify condition to use libc++
> 
> This CL simplifies use_custom_libcxx.  Most of the sanitizers are only
> used on Linux so those cases can be removed.
> 
> BUG=593874
> R=thakis@chromium.org
> CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_chromium_msan_rel_ng;master.tryserver.chromium.linux:linux_chromium_tsan_rel_ng;master.tryserver.chromium.linux:linux_chromium_ubsan_rel_ng
> 
> Review-Url: https://codereview.chromium.org/2963183003
> Cr-Commit-Position: refs/heads/master@{#483787}
> Committed: https://chromium.googlesource.com/chromium/src/+/3b5152538d133f59aa6709a0811ff6c745973cc6

TBR=thakis@chromium.org,thomasanderson@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=593874
Review-Url: https://codereview.chromium.org/2966893002
Cr-Commit-Position: refs/heads/master@{#483814}
Committed: https://chromium.googlesource.com/chromium/src/+/d667444e9a52506535575a508d35dd9cede6d49b

[findit-for-me, 2017-06-30 21:08:05]

Created Revert of Simplify condition to use libc++

[findit-for-me, 2017-06-30 21:08:05]

findit-for-me@appspot.gserviceaccount.com changed reviewers:
+ maniscalco@google.com, mkwst@google.com, penghuang@google.com,
petermayo@google.com, timloh@google.com

[findit-for-me, 2017-06-30 21:08:06]

Sheriffs, CL owner or CL reviewers:

Please confirm and "Quick L-G-T-M & CQ" this revert if it is correct.
If it is a false positive, please close it.

Findit (https://goo.gl/kROfz5) identified the original CL as the culprit
for failures in the build cycles as shown on:
https://findit-for-me.appspot.com/waterfall/culprit?key=ag9zfmZpbmRpdC1mb3Itb...

[Tom Anderson, 2017-06-30 21:13:20]

The CQ bit was checked by thomasanderson@chromium.org

[Tom Anderson, 2017-06-30 21:13:20]

lgtm

[commit-bot: I haz the power, 2017-06-30 21:13:38]

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, 2017-06-30 21:14:01]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1498857200196480, "parent_rev":
"3e8047dfdb365ced762ab524b9082346e29ef4fb", "commit_rev":
"d667444e9a52506535575a508d35dd9cede6d49b"}

[commit-bot: I haz the power, 2017-06-30 21:14:17]

Description was changed from

==========
Revert of Simplify condition to use libc++ (patchset #2 id:20001 of
https://codereview.chromium.org/2963183003/ )

Reason for revert:

Findit (https://goo.gl/kROfz5) identified CL at revision 483787 as the
culprit for failures in the build cycles as shown on:
https://findit-for-me.appspot.com/waterfall/culprit?key=ag9zfmZpbmRpdC1mb3Itb...

Original issue's description:
> Simplify condition to use libc++
> 
> This CL simplifies use_custom_libcxx.  Most of the sanitizers are only
> used on Linux so those cases can be removed.
> 
> BUG=593874
> R=thakis@chromium.org
>
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_chromium_msan_rel_ng;master.tryserver.chromium.linux:linux_chromium_tsan_rel_ng;master.tryserver.chromium.linux:linux_chromium_ubsan_rel_ng
> 
> Review-Url: https://codereview.chromium.org/2963183003
> Cr-Commit-Position: refs/heads/master@{#483787}
> Committed:
https://chromium.googlesource.com/chromium/src/+/3b5152538d133f59aa6709a0811f...

TBR=thakis@chromium.org,thomasanderson@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=593874
==========

to

==========
Revert of Simplify condition to use libc++ (patchset #2 id:20001 of
https://codereview.chromium.org/2963183003/ )

Reason for revert:

Findit (https://goo.gl/kROfz5) identified CL at revision 483787 as the
culprit for failures in the build cycles as shown on:
https://findit-for-me.appspot.com/waterfall/culprit?key=ag9zfmZpbmRpdC1mb3Itb...

Original issue's description:
> Simplify condition to use libc++
> 
> This CL simplifies use_custom_libcxx.  Most of the sanitizers are only
> used on Linux so those cases can be removed.
> 
> BUG=593874
> R=thakis@chromium.org
>
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_chromium_msan_rel_ng;master.tryserver.chromium.linux:linux_chromium_tsan_rel_ng;master.tryserver.chromium.linux:linux_chromium_ubsan_rel_ng
> 
> Review-Url: https://codereview.chromium.org/2963183003
> Cr-Commit-Position: refs/heads/master@{#483787}
> Committed:
https://chromium.googlesource.com/chromium/src/+/3b5152538d133f59aa6709a0811f...

TBR=thakis@chromium.org,thomasanderson@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=593874

Review-Url: https://codereview.chromium.org/2966893002
Cr-Commit-Position: refs/heads/master@{#483814}
Committed:
https://chromium.googlesource.com/chromium/src/+/d667444e9a52506535575a508d35...
==========

[commit-bot: I haz the power, 2017-06-30 21:14:20]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/d667444e9a52506535575a508d35...