Reland Device Orientation API on Chrome OS

Reland Device Orientation API on Chrome OS

This reverts commit cc6a8bfeb49e93068e8df28f406e6ad0b5d6915e.
From review: https://codereview.chromium.org/899973002/

Original issue's description:
> Device Orientation API on Chrome OS
>
> Implement DataFetcherSharedMemory on Chrome OS to provide Device Orientation support. Create SensorManagerChromeOS to observe accelerometer events, and to generate updates to the Device Orientation API.
>
> This is a follow up to: https://codereview.chromium.org/680383007/
>
> With the accelerometer on Chrome OS now exposed to content/ from chromeos/accelerometer, no ash/ implementation is required. No public api in content/public/browser is needed either.
>
> TEST=SensorManagerTest.OrientationBuffer, SensorManagerTest.NeutralOrientation, SensorManagerTest.UpsideDown, SensorManagerTest.BeforeUpsideDownBoundary, SensorManagerTest.LeftEdge, SensorManagerTest.RightEdge, SensorManagerTest.BeforeRightEdgeBoundary
> BUG=342908
TBR=timvolodine@chromium.org,jam@chromium.org
BUG=342908
Committed: https://crrev.com/a6725f19e83a67b453db83f15c4191b2785de60a
Cr-Commit-Position: refs/heads/master@{#314692}

[jonross, 2015-02-04 23:11:32]

jonross@chromium.org changed reviewers:
+ jam@chromium.org, timvolodine@chromium.org

[jonross, 2015-02-04 23:21:49]

The CQ bit was checked by jonross@chromium.org

[commit-bot: I haz the power, 2015-02-04 23:22:26]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/880083005/20001

[commit-bot: I haz the power, 2015-02-05 00:53:21]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-02-05 00:55:32]

Patchset 2 (id:??) landed as
https://crrev.com/a6725f19e83a67b453db83f15c4191b2785de60a
Cr-Commit-Position: refs/heads/master@{#314692}