Add CHECKs to find root cause of Windows-only crash.

Add CHECKs to find root cause of Windows-only crash.
Checks are temporary and would be in canary only.
For gory details please see original bug 108685.

BUG=109757
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=117268

[enal, 2012-01-10 18:47:08]

Sending CL that temporary adds CHECKs().

[cpu_(ooo_6.6-7.5), 2012-01-11 01:00:39]

lgtm with the changes noted.

Also please manually run the media audio tests, to make sure we don't crash
every time.

http://codereview.chromium.org/9147039/diff/1/media/audio/win/waveout_output_...
File media/audio/win/waveout_output_win.cc (right):

http://codereview.chromium.org/9147039/diff/1/media/audio/win/waveout_output_...
media/audio/win/waveout_output_win.cc:222: CHECK_EQ(result,
static_cast<MMRESULT>(MMSYSERR_NOERROR));
in here (and some other cases) you are testing the very condition tested in line
221. what you want is CHECK(false) or whatever the fanciest version is.

http://codereview.chromium.org/9147039/diff/1/media/audio/win/waveout_output_...
media/audio/win/waveout_output_win.cc:283: CHECK_NE(unregister, FALSE);
same here.

[commit-bot: I haz the power, 2012-01-11 18:04:59]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/enal@chromium.org/9147039/3001

[commit-bot: I haz the power, 2012-01-11 18:05:00]

Can't apply patch for file media/audio/win/waveout_output_win.cc.
While running patch -p0 --forward --force;
patching file media/audio/win/waveout_output_win.cc
Hunk #12 FAILED at 297.
Hunk #13 succeeded at 317 (offset 2 lines).
1 out of 13 hunks FAILED -- saving rejects to file
media/audio/win/waveout_output_win.cc.rej

[commit-bot: I haz the power, 2012-01-11 18:56:53]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/enal@chromium.org/9147039/4006

[commit-bot: I haz the power, 2012-01-11 20:06:15]

Change committed as 117268