Implement break signal for serial api.

Implement break signal for serial api.

`Break` is somewhat related to control signaling and holds tx line low for n milliseconds.
Adding platform specific implementation.

BUG=461169
TEST=Manual with attached application on crbug.com/461169

Committed: https://crrev.com/d169ad87e2bc70b51a52bf5fbc2fbe9db6c8ed01
Cr-Commit-Position: refs/heads/master@{#334111}

[limasdf, 2015-06-10 17:39:24]

Patchset #1 (id:1) has been deleted

[limasdf, 2015-06-10 17:39:32]

Patchset #1 (id:20001) has been deleted

[limasdf, 2015-06-10 17:50:50]

limasdf@gmail.com changed reviewers:
+ rockot@chromium.org

[limasdf, 2015-06-10 17:50:59]

Patchset #1 (id:40001) has been deleted

[limasdf, 2015-06-10 17:52:17]

Hi. Rockot.
Would you mind taking a look?

[Ken Rockot(use gerrit already), 2015-06-10 19:07:18]

please update tools/metrics/histograms/histograms.xml to add the new functions
to the "ExtensionFunctions" enum.

https://codereview.chromium.org/1128943005/diff/60001/device/serial/serial_io...
File device/serial/serial_io_handler.h (right):

https://codereview.chromium.org/1128943005/diff/60001/device/serial/serial_io...
device/serial/serial_io_handler.h:47: // while a Write is already pending.
Otherwise, the Done or DoneWithError //
please remove this change

[Ken Rockot(use gerrit already), 2015-06-10 19:09:48]

On 2015/06/10 19:07:18, Ken Rockot wrote:
> please update tools/metrics/histograms/histograms.xml to add the new functions
> to the "ExtensionFunctions" enum.

you can run python tools/metrics/histograms/update_extension_functions.pt to do
this btw

[Ken Rockot(use gerrit already), 2015-06-10 19:10:01]

On 2015/06/10 19:09:48, Ken Rockot wrote:
> On 2015/06/10 19:07:18, Ken Rockot wrote:
> > please update tools/metrics/histograms/histograms.xml to add the new
functions
> > to the "ExtensionFunctions" enum.
> 
> you can run python tools/metrics/histograms/update_extension_functions.pt to
do
> this btw

.py, not .pt :)

[Ken Rockot(use gerrit already), 2015-06-10 19:37:05]

rockot@chromium.org changed reviewers:
+ reillyg@chromium.org

[Ken Rockot(use gerrit already), 2015-06-10 19:37:05]

This hasn't undergone the standard API review process for apps/extensions APIs.
Because I think this is a totally non-controversial change, I'd rather not
impose that process on you here. Still, +reillyg in case I'm missing some
element of risk.

[Reilly Grant (use Gerrit), 2015-06-10 19:42:13]

I agree with Ken. Totally uncontroversial.

https://codereview.chromium.org/1128943005/diff/60001/device/serial/serial_io...
File device/serial/serial_io_handler_posix.cc (right):

https://codereview.chromium.org/1128943005/diff/60001/device/serial/serial_io...
device/serial/serial_io_handler_posix.cc:476: return
ioctl(file().GetPlatformFile(), TIOCSBRK, 0) == 0;
Please catch errors here and use a VPLOG to record them.

https://codereview.chromium.org/1128943005/diff/60001/device/serial/serial_io...
device/serial/serial_io_handler_posix.cc:480: return
ioctl(file().GetPlatformFile(), TIOCCBRK, 0) == 0;
Same here.

https://codereview.chromium.org/1128943005/diff/60001/device/serial/serial_io...
File device/serial/serial_io_handler_win.cc (right):

https://codereview.chromium.org/1128943005/diff/60001/device/serial/serial_io...
device/serial/serial_io_handler_win.cc:395: return
SetCommBreak(file().GetPlatformFile()) != 0;
And here.

https://codereview.chromium.org/1128943005/diff/60001/device/serial/serial_io...
device/serial/serial_io_handler_win.cc:399: return
ClearCommBreak(file().GetPlatformFile()) != 0;
And here.

[limasdf, 2015-06-11 22:14:24]

ptal

https://codereview.chromium.org/1128943005/diff/60001/device/serial/serial_io...
File device/serial/serial_io_handler.h (right):

https://codereview.chromium.org/1128943005/diff/60001/device/serial/serial_io...
device/serial/serial_io_handler.h:47: // while a Write is already pending.
Otherwise, the Done or DoneWithError //
On 2015/06/10 19:07:18, Ken Rockot wrote:
> please remove this change

Done.

https://codereview.chromium.org/1128943005/diff/60001/device/serial/serial_io...
File device/serial/serial_io_handler_posix.cc (right):

https://codereview.chromium.org/1128943005/diff/60001/device/serial/serial_io...
device/serial/serial_io_handler_posix.cc:476: return
ioctl(file().GetPlatformFile(), TIOCSBRK, 0) == 0;
On 2015/06/10 19:42:13, reillyg wrote:
> Please catch errors here and use a VPLOG to record them.

Done.

https://codereview.chromium.org/1128943005/diff/60001/device/serial/serial_io...
device/serial/serial_io_handler_posix.cc:480: return
ioctl(file().GetPlatformFile(), TIOCCBRK, 0) == 0;
On 2015/06/10 19:42:13, reillyg wrote:
> Same here.

Done.

https://codereview.chromium.org/1128943005/diff/60001/device/serial/serial_io...
File device/serial/serial_io_handler_win.cc (right):

https://codereview.chromium.org/1128943005/diff/60001/device/serial/serial_io...
device/serial/serial_io_handler_win.cc:395: return
SetCommBreak(file().GetPlatformFile()) != 0;
On 2015/06/10 19:42:13, reillyg wrote:
> And here.

Done.

https://codereview.chromium.org/1128943005/diff/60001/device/serial/serial_io...
device/serial/serial_io_handler_win.cc:399: return
ClearCommBreak(file().GetPlatformFile()) != 0;
On 2015/06/10 19:42:13, reillyg wrote:
> And here.

Done.

[Ken Rockot(use gerrit already), 2015-06-11 22:16:22]

lgtm. thanks for this patch

[limasdf, 2015-06-11 22:17:06]

thanks for the quick review

[limasdf, 2015-06-11 22:17:15]

The CQ bit was checked by limasdf@gmail.com

[commit-bot: I haz the power, 2015-06-11 22:18:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1128943005/80001

[commit-bot: I haz the power, 2015-06-11 22:28:45]

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

[commit-bot: I haz the power, 2015-06-11 22:28:46]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[limasdf, 2015-06-11 22:31:25]

limasdf@gmail.com changed reviewers:
+ isherman@chromium.org

[limasdf, 2015-06-11 22:32:30]

Ilya Sherman, Could you take a look tools/metrics/histograms/histograms.xml?

[Ilya Sherman, 2015-06-12 01:31:37]

histograms lgtm

[limasdf, 2015-06-12 01:35:03]

The CQ bit was checked by limasdf@gmail.com

[commit-bot: I haz the power, 2015-06-12 01:35:59]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1128943005/80001

[commit-bot: I haz the power, 2015-06-12 02:06:28]

Committed patchset #2 (id:80001)

[commit-bot: I haz the power, 2015-06-12 02:07:29]

Patchset 2 (id:??) landed as
https://crrev.com/d169ad87e2bc70b51a52bf5fbc2fbe9db6c8ed01
Cr-Commit-Position: refs/heads/master@{#334111}