Change AccelerometerReader to a Singleton

Change AccelerometerReader to a Singleton

On ChromeOS the accelerometer needs to be read by both ash/ and content/

This change removes the ownership of AccelerometerReader from Shell, changing it into a Singleton.

TEST=Confirmed that a device with an accelerometer enters maximize mode.
BUG=342908
Committed: https://crrev.com/9d6537c061de117ef7a82d214534798e0d7e1d1b
Cr-Commit-Position: refs/heads/master@{#311353}

[jonross, 2015-01-07 15:34:06]

jonross@chromium.org changed reviewers:
+ oshima@chromium.org

[jonross, 2015-01-07 15:34:07]

Hi Oshima,

Could you provide a review for this change?

On Chrome OS there is now a need for both ash/ and content/ to access the
AccelerometerReader. So I am removing Shell's ownership of it, to convert it to
a Singleton.

Thanks,
Jon

[oshima, 2015-01-07 16:39:57]

https://codereview.chromium.org/822503003/diff/1/chromeos/accelerometer/accel...
File chromeos/accelerometer/accelerometer_reader.cc (right):

https://codereview.chromium.org/822503003/diff/1/chromeos/accelerometer/accel...
chromeos/accelerometer/accelerometer_reader.cc:190:
LeakySingletonTraits<AccelerometerReader>>::get();
why this needs to be leaky?

[jonross, 2015-01-07 19:54:52]

On 2015/01/07 16:39:57, oshima wrote:
>
https://codereview.chromium.org/822503003/diff/1/chromeos/accelerometer/accel...
> File chromeos/accelerometer/accelerometer_reader.cc (right):
> 
>
https://codereview.chromium.org/822503003/diff/1/chromeos/accelerometer/accel...
> chromeos/accelerometer/accelerometer_reader.cc:190:
> LeakySingletonTraits<AccelerometerReader>>::get();
> why this needs to be leaky?

The access from ash and content will be on different threads. I saw the leaky
version already in use within content for multi-threaded access.

[jonross, 2015-01-12 15:15:46]

https://codereview.chromium.org/822503003/diff/1/chromeos/accelerometer/accel...
File chromeos/accelerometer/accelerometer_reader.cc (right):

https://codereview.chromium.org/822503003/diff/1/chromeos/accelerometer/accel...
chromeos/accelerometer/accelerometer_reader.cc:190:
LeakySingletonTraits<AccelerometerReader>>::get();
On 2015/01/07 16:39:57, oshima wrote:
> why this needs to be leaky?

As discussed offline this is not necessary. Thanks for the clarification.

I've changed this to use a normal Singleton.

[oshima, 2015-01-12 22:56:38]

lgtm

[jonross, 2015-01-13 01:27:09]

The CQ bit was checked by jonross@chromium.org

[commit-bot: I haz the power, 2015-01-13 01:28:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/822503003/20001

[commit-bot: I haz the power, 2015-01-13 02:10:04]

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

[commit-bot: I haz the power, 2015-01-13 02:10:05]

Try jobs failed on following builders:
  linux_chromium_chromeos_rel_ng on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[jonross, 2015-01-13 21:48:32]

The CQ bit was checked by jonross@chromium.org

[commit-bot: I haz the power, 2015-01-13 21:48:54]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/822503003/80001

[commit-bot: I haz the power, 2015-01-13 22:45:29]

Committed patchset #5 (id:80001)

[commit-bot: I haz the power, 2015-01-13 22:46:32]

Patchset 5 (id:??) landed as
https://crrev.com/9d6537c061de117ef7a82d214534798e0d7e1d1b
Cr-Commit-Position: refs/heads/master@{#311353}