Revert of Add libc++ __tree to ubsan blacklist.

Revert of Add libc++ __tree to ubsan blacklist. (patchset #2 id:20001 of https://codereview.chromium.org/2109663003/ )

Reason for revert:
Issued fixed upstream

Original issue's description:
> Add libc++ __tree to ubsan blacklist.
> 
> libc++ __tree is not ubsan clean. It floods compile and run steps
> with "runtime error: downcast" and "runtime error: upcast" errors,
> making ubsan much less usable.
> This is a KI with libc++: https://llvm.org/bugs/show_bug.cgi?id=19302
> 
> Committed: https://crrev.com/e2abe2366d707ac6ad308e2643f41423971f81fc
> Cr-Commit-Position: refs/heads/master@{#402902}

TBR=dpranke@chromium.org,ochang@chromium.org,thakis@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.

Review-Url: https://codereview.chromium.org/2983093003
Cr-Commit-Position: refs/heads/master@{#487986}
Committed: https://chromium.googlesource.com/chromium/src/+/a04bfdb5ee615dc24bb29a74e17409c4922e351a

[mbjorge, 2017-07-19 20:40:06]

The CQ bit was checked by mbjorge@chromium.org

[mbjorge, 2017-07-19 20:40:06]

Created Revert of Add libc++ __tree to ubsan blacklist.

[commit-bot: I haz the power, 2017-07-19 20:40:26]

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, 2017-07-19 20:40:28]

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

[commit-bot: I haz the power, 2017-07-19 20:40:29]

No L-G-T-M from a valid reviewer yet.
CQ run can only be started once the patch has received an L-G-T-M from a full
committer.
Even if an L-G-T-M may have been provided, it was from a non-committer,_not_ a
full super star committer.
Committers are members of the group "project-chromium-committers".
Note that this has nothing to do with OWNERS files.

[mbjorge, 2017-07-19 20:40:55]

Tested compiling/running locally with the revert and didn't see the flood of
runtime errors, so it appears to be fixed

[Nico, 2017-07-19 20:45:13]

lgtm, nice, thanks!

[mbjorge, 2017-07-19 20:45:39]

The CQ bit was checked by mbjorge@chromium.org

[commit-bot: I haz the power, 2017-07-19 20:45:55]

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, 2017-07-19 21:16:16]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1500497139560970, "parent_rev":
"e48c97172adf7ce5dea624f74ac5f597cd0dd62d", "commit_rev":
"a04bfdb5ee615dc24bb29a74e17409c4922e351a"}

[commit-bot: I haz the power, 2017-07-19 21:16:30]

Description was changed from

==========
Revert of Add libc++ __tree to ubsan blacklist. (patchset #2 id:20001 of
https://codereview.chromium.org/2109663003/ )

Reason for revert:
Issued fixed upstream

Original issue's description:
> Add libc++ __tree to ubsan blacklist.
> 
> libc++ __tree is not ubsan clean. It floods compile and run steps
> with "runtime error: downcast" and "runtime error: upcast" errors,
> making ubsan much less usable.
> This is a KI with libc++: https://llvm.org/bugs/show_bug.cgi?id=19302
> 
> Committed: https://crrev.com/e2abe2366d707ac6ad308e2643f41423971f81fc
> Cr-Commit-Position: refs/heads/master@{#402902}

TBR=dpranke@chromium.org,ochang@chromium.org,thakis@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
==========

to

==========
Revert of Add libc++ __tree to ubsan blacklist. (patchset #2 id:20001 of
https://codereview.chromium.org/2109663003/ )

Reason for revert:
Issued fixed upstream

Original issue's description:
> Add libc++ __tree to ubsan blacklist.
> 
> libc++ __tree is not ubsan clean. It floods compile and run steps
> with "runtime error: downcast" and "runtime error: upcast" errors,
> making ubsan much less usable.
> This is a KI with libc++: https://llvm.org/bugs/show_bug.cgi?id=19302
> 
> Committed: https://crrev.com/e2abe2366d707ac6ad308e2643f41423971f81fc
> Cr-Commit-Position: refs/heads/master@{#402902}

TBR=dpranke@chromium.org,ochang@chromium.org,thakis@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.

Review-Url: https://codereview.chromium.org/2983093003
Cr-Commit-Position: refs/heads/master@{#487986}
Committed:
https://chromium.googlesource.com/chromium/src/+/a04bfdb5ee615dc24bb29a74e174...
==========

[commit-bot: I haz the power, 2017-07-19 21:16:31]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/a04bfdb5ee615dc24bb29a74e174...

[Dirk Pranke, 2017-07-20 00:06:12]

lgtm