Fix ENABLE_THREAD_CHECKER

Fix ENABLE_THREAD_CHECKER

We've found base/threading/thread_checker_impl.h was included
when NDEBUG was defined (and DCHECK_ALWAYS_ON was not defined)
with cl.exe.

For example,
 > type a.c
 #define FOO
 #define ENABLE (!defined(FOO))
 #if ENABLE
 enabled
 #endif
 > cl /nologo /E a.c
 a.c
 #line 1 "a.c"

 enabled
 #line 6 "a.c"

BUG=none
TEST=none


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=138755

[Jói, 2012-05-23 09:38:42]

LGTM

Wow, I feel bad about this bug, thanks for fixing it.  In my initial version of
this change, I did this the way you have now fixed it, then changed it based on
review comments (see diff from patchset 2 to 3 at
http://codereview.chromium.org/9020008/diff2/3001:3002/base/threading/thread_...).

I probably only did thorough testing on the version before the change, that is
how this problem crept in.

Again, thanks for catching this and fixing it.

Cheers,
Jói

[commit-bot: I haz the power, 2012-05-23 10:06:55]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ukai@chromium.org/10414072/2001

[commit-bot: I haz the power, 2012-05-23 10:06:58]

Presubmit check for 10414072-2001 failed and returned exit status 1.

Running presubmit commit checks ...

** Presubmit ERRORS **
Missing LGTM from an OWNER for files in these directories:
    base/threading

[jam, 2012-05-23 17:24:21]

lgtm

[jam, 2012-05-23 17:24:45]

actually, i thought this was thread_restrictions.h. i'm not an owner for
thread_checker.h

[jar (doing other things), 2012-05-23 18:22:18]

lgtm

[commit-bot: I haz the power, 2012-05-23 23:53:12]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ukai@chromium.org/10414072/2001

[commit-bot: I haz the power, 2012-05-24 08:59:39]

Change committed as 138755