Switch thread_local to use chromium's TLS implementation

Switch thread_local to use chromium's TLS implementation

This patch switch thread_local to use ThreadLocalStorage::Slot, so it get the
TLS slot from the chromium's TLS instead of OS's.

There is debate whether the Windows' TLS's destructor implementation is reliable
or not, if we are able to remove all the use of TLS destructor, only ThreadLocalStorage::Slot
needs to change, as thread_local doesn't use TLS destructor at all.

BUG=264406
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=254986

[brettw, 2014-01-26 06:35:08]

This patch looks fine, but I don't quite follow the second part of the commit
message about destructors. Can you expand on this a bit? "if we are able"
implies to me that it's something we'd like to do but might be difficult, but
from the rest of the context I suspect you mean "if we don't have a destructor
at all nothing will change."

[michaelbai, 2014-01-27 04:27:22]

On 2014/01/26 06:35:08, brettw wrote:
> This patch looks fine, but I don't quite follow the second part of the commit
> message about destructors. Can you expand on this a bit? "if we are able"
> implies to me that it's something we'd like to do but might be difficult, but
> from the rest of the context I suspect you mean "if we don't have a destructor
> at all nothing will change."

Check the bug comments #17 - #29, there was a discussion whether we should rely
on TLS destructor.
In description, I just want to emphasize this patch doesn't change anything
related to TLS destructor,
if we are able to remove the TLS destructor in the future, there is nothing need
to change here.

[brettw, 2014-01-27 04:31:29]

I'm not arguing about whether this patch is OK, I'm saying your commit message
is unclear and it should be expanded.

[michaelbai, 2014-01-27 05:33:36]

Description updated, PTAL

[brettw, 2014-01-27 06:24:36]

Great, that's a lot easier to follow. LGTM

[commit-bot: I haz the power, 2014-01-27 17:11:55]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/michaelbai@chromium.org/139633003/1

[commit-bot: I haz the power, 2014-01-27 18:02:07]

Retried try job too often on ios_dbg_simulator for step(s) base_unittests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=ios_dbg_si...

[michaelbai, 2014-02-03 20:42:36]

Hi Brett,

PTAL, I have increased the TLS slot to 256 to pass the iOS's base test, it
totally uses about 180 slots, the iOS has 512 system TLS slots, but 256 is
sufficient for us now.

[michaelbai, 2014-03-04 18:36:34]

The CQ bit was checked by michaelbai@chromium.org

[commit-bot: I haz the power, 2014-03-04 18:36:42]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/michaelbai@chromium.org/139633003/350001

[commit-bot: I haz the power, 2014-03-04 18:59:27]

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

[commit-bot: I haz the power, 2014-03-04 18:59:28]

Retried try job too often on win_rel for step(s) base_unittests, browser_tests,
interactive_ui_tests, net_unittests, unit_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...

[michaelbai, 2014-03-04 19:04:15]

The CQ bit was checked by michaelbai@chromium.org

[commit-bot: I haz the power, 2014-03-04 19:07:59]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/michaelbai@chromium.org/139633003/420001

[commit-bot: I haz the power, 2014-03-04 20:49:14]

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

[commit-bot: I haz the power, 2014-03-04 20:49:14]

Retried try job too often on win_rel for step(s) unit_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...

[michaelbai, 2014-03-05 04:07:53]

The CQ bit was checked by michaelbai@chromium.org

[commit-bot: I haz the power, 2014-03-05 04:08:14]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/michaelbai@chromium.org/139633003/420001

[commit-bot: I haz the power, 2014-03-05 09:52:55]

Change committed as 254986