mash: Provide a fake chromeos StatisticsProvider in ash

mash: Provide a fake chromeos StatisticsProvider in ash

Lower-level code in //chromeos (like the power manager client) assumes it can
use chromeos::system::StatisticsProvider to determine if it is running in a VM
(among other things). This is causing CHECK failures on mash when powerd isn't
running.

For now, provide a fake implementation, since we don't want to create a
StatisticsProviderImpl in both chrome and ash, as it runs an external binary
to get its information, and we don't want to do that twice.

BUG=643289
TEST=manual, stop powerd, start chrome on device with --mash, no CHECK failure

Committed: https://crrev.com/fb20f602654bb390e495835aa5087f98d88143a5
Cr-Commit-Position: refs/heads/master@{#416088}

[James Cook, 2016-09-01 20:52:13]

jamescook@chromium.org changed reviewers:
+ derat@chromium.org

[James Cook, 2016-09-01 20:52:14]

derat, please take a look

kylechar, just FYI

[James Cook, 2016-09-01 20:52:21]

The CQ bit was checked by jamescook@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-09-01 20:53:07]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[Daniel Erat, 2016-09-01 21:07:10]

lgtm

https://codereview.chromium.org/2297193007/diff/20001/chromeos/chromeos.gyp
File chromeos/chromeos.gyp (right):

https://codereview.chromium.org/2297193007/diff/20001/chromeos/chromeos.gyp#n...
chromeos/chromeos.gyp:366: # Used when running mash, both on Linux and on real
devices.
maybe put blank lines on either side of the block so it's clear what the comment
is referring to? (or perhaps this formatting is required)

i'd also be happy if this were only built for mash, but that may be harder to
do. :-)

[James Cook, 2016-09-01 21:21:41]

Thanks for the quick review.

https://codereview.chromium.org/2297193007/diff/20001/chromeos/chromeos.gyp
File chromeos/chromeos.gyp (right):

https://codereview.chromium.org/2297193007/diff/20001/chromeos/chromeos.gyp#n...
chromeos/chromeos.gyp:366: # Used when running mash, both on Linux and on real
devices.
On 2016/09/01 21:07:09, Daniel Erat wrote:
> maybe put blank lines on either side of the block so it's clear what the
comment
> is referring to? (or perhaps this formatting is required)
> 
> i'd also be happy if this were only built for mash, but that may be harder to
> do. :-)

Blank lines added.

It turns out to be annoyingly difficult to make this only build for mash. We
don't have any global defines or build settings for mash. It's just another
build target. Chrome happens to launch the executable when you run chrome
--mash, but otherwise it's stock ash.

[James Cook, 2016-09-01 21:21:44]

The CQ bit was checked by jamescook@chromium.org

[James Cook, 2016-09-01 21:21:45]

The patchset sent to the CQ was uploaded after l-g-t-m from derat@chromium.org
Link to the patchset: https://codereview.chromium.org/2297193007/#ps40001
(title: "build file")

[commit-bot: I haz the power, 2016-09-01 21:22:18]

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, 2016-09-01 22:34:37]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-09-01 22:36:09]

Description was changed from

==========
mash: Provide a fake chromeos StatisticsProvider in ash

Lower-level code in //chromeos (like the power manager client) assumes it can
use chromeos::system::StatisticsProvider to determine if it is running in a VM
(among other things). This is causing CHECK failures on mash when powerd isn't
running.

For now, provide a fake implementation, since we don't want to create a
StatisticsProviderImpl in both chrome and ash, as it runs an external binary
to get its information, and we don't want to do that twice.

BUG=643289
TEST=manual, stop powerd, start chrome on device with --mash, no CHECK failure
==========

to

==========
mash: Provide a fake chromeos StatisticsProvider in ash

Lower-level code in //chromeos (like the power manager client) assumes it can
use chromeos::system::StatisticsProvider to determine if it is running in a VM
(among other things). This is causing CHECK failures on mash when powerd isn't
running.

For now, provide a fake implementation, since we don't want to create a
StatisticsProviderImpl in both chrome and ash, as it runs an external binary
to get its information, and we don't want to do that twice.

BUG=643289
TEST=manual, stop powerd, start chrome on device with --mash, no CHECK failure

Committed: https://crrev.com/fb20f602654bb390e495835aa5087f98d88143a5
Cr-Commit-Position: refs/heads/master@{#416088}
==========

[commit-bot: I haz the power, 2016-09-01 22:36:10]

Patchset 3 (id:??) landed as
https://crrev.com/fb20f602654bb390e495835aa5087f98d88143a5
Cr-Commit-Position: refs/heads/master@{#416088}