Revert of Temporarily CHECK use after free in Value

Revert of Temporarily CHECK use after free in Value (patchset #1 id:1 of https://codereview.chromium.org/2743363004/ )

Reason for revert:
Removing the temporary CHECK. As explained in https://crbug.com/697817#c13, it ended up inconclusive, and it also does not protect completely against the use of corrupted memory.

Original issue's description:
> Temporarily CHECK use after free in Value
> 
> One of the hypotheses for https://crbug.com/697817 is that a Value is used
> after free (see #5 there). To verify/refute that hypothesis, this CL
> temporarily introduces and CHECKS an |alive_| flag. This change will be
> reverted after a couple of days in Canary, and only serves investigation
> purposes.
> 
> BUG=697817
> 
> Review-Url: https://codereview.chromium.org/2743363004
> Cr-Commit-Position: refs/heads/master@{#456801}
> Committed: https://chromium.googlesource.com/chromium/src/+/e2477101857d4c38dd2eb7fb67312b7fd0022f5e

TBR=brettw@chromium.org,jdoerrie@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=697817
Review-Url: https://codereview.chromium.org/2761773005
Cr-Commit-Position: refs/heads/master@{#458200}
Committed: https://chromium.googlesource.com/chromium/src/+/ab5ed281e1f137f46e2a0d0daeda3273b04c733d

[vabr (Chromium), 2017-03-20 20:12:06]

The CQ bit was checked by vabr@chromium.org

[vabr (Chromium), 2017-03-20 20:12:06]

Created Revert of Temporarily CHECK use after free in Value

[commit-bot: I haz the power, 2017-03-20 20:12:37]

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, 2017-03-20 22:20:04]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1490040726385180, "parent_rev":
"b2ea0a474e990d96b9e9580001da95efba3561b3", "commit_rev":
"ab5ed281e1f137f46e2a0d0daeda3273b04c733d"}

[commit-bot: I haz the power, 2017-03-20 22:21:18]

Description was changed from

==========
Revert of Temporarily CHECK use after free in Value (patchset #1 id:1 of
https://codereview.chromium.org/2743363004/ )

Reason for revert:
Removing the temporary CHECK. As explained in https://crbug.com/697817#c13, it
ended up inconclusive, and it also does not protect completely against the use
of corrupted memory.

Original issue's description:
> Temporarily CHECK use after free in Value
> 
> One of the hypotheses for https://crbug.com/697817 is that a Value is used
> after free (see #5 there). To verify/refute that hypothesis, this CL
> temporarily introduces and CHECKS an |alive_| flag. This change will be
> reverted after a couple of days in Canary, and only serves investigation
> purposes.
> 
> BUG=697817
> 
> Review-Url: https://codereview.chromium.org/2743363004
> Cr-Commit-Position: refs/heads/master@{#456801}
> Committed:
https://chromium.googlesource.com/chromium/src/+/e2477101857d4c38dd2eb7fb6731...

TBR=brettw@chromium.org,jdoerrie@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=697817
==========

to

==========
Revert of Temporarily CHECK use after free in Value (patchset #1 id:1 of
https://codereview.chromium.org/2743363004/ )

Reason for revert:
Removing the temporary CHECK. As explained in https://crbug.com/697817#c13, it
ended up inconclusive, and it also does not protect completely against the use
of corrupted memory.

Original issue's description:
> Temporarily CHECK use after free in Value
> 
> One of the hypotheses for https://crbug.com/697817 is that a Value is used
> after free (see #5 there). To verify/refute that hypothesis, this CL
> temporarily introduces and CHECKS an |alive_| flag. This change will be
> reverted after a couple of days in Canary, and only serves investigation
> purposes.
> 
> BUG=697817
> 
> Review-Url: https://codereview.chromium.org/2743363004
> Cr-Commit-Position: refs/heads/master@{#456801}
> Committed:
https://chromium.googlesource.com/chromium/src/+/e2477101857d4c38dd2eb7fb6731...

TBR=brettw@chromium.org,jdoerrie@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=697817

Review-Url: https://codereview.chromium.org/2761773005
Cr-Commit-Position: refs/heads/master@{#458200}
Committed:
https://chromium.googlesource.com/chromium/src/+/ab5ed281e1f137f46e2a0d0daeda...
==========

[commit-bot: I haz the power, 2017-03-20 22:21:18]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/ab5ed281e1f137f46e2a0d0daeda...