Revert of Re-enable ScreenOrientationBrowserTests on Chrome OS

Revert of Re-enable ScreenOrientationBrowserTests on Chrome OS (patchset #1 id:1 of https://codereview.chromium.org/1225093002/)

Reason for revert:
Unfortunately, the tests still flake a lot:

http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Ozone%20Tests%20%281%29/builds/17013/steps/content_browsertests/logs/ScreenOrientationBrowserTest.WindowOrientationChange
http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Ozone%20Tests%20%281%29/builds/17014/steps/content_browsertests/logs/ScreenOrientationBrowserTest.ScreenOrientationChange

Original issue's description:
> Re-enable ScreenOrientationBrowserTests on Chrome OS
> Two tests were flaking on Chrome OS builds.
>
> Re-enabling to confirm that fixes to Screen Orientation API also fixed these tests.
>
> TEST=ScreenOrientationBrowserTest.ScreenOrientationChange,
> ScreenOrientationBrowserTest.WindowOrientationChange
> BUG=468259
>
> Committed: https://crrev.com/4fa07d46cbdea4b263ad07beca29f90b42757c67
> Cr-Commit-Position: refs/heads/master@{#337950}

TBR=mlamouri@chromium.org,jonross@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=468259
Committed: https://crrev.com/a6caa4b3bd9d29995c85dd8b8e75f0986125faf8
Cr-Commit-Position: refs/heads/master@{#338008}

[Mattias Nissler (ping if slow), 2015-07-09 10:03:22]

Created Revert of Re-enable ScreenOrientationBrowserTests on Chrome OS

[commit-bot: I haz the power, 2015-07-09 10:03:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1227163004/1

[commit-bot: I haz the power, 2015-07-09 10:04:16]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-09 10:04:59]

Patchset 1 (id:??) landed as
https://crrev.com/a6caa4b3bd9d29995c85dd8b8e75f0986125faf8
Cr-Commit-Position: refs/heads/master@{#338008}