Revert "Allow aria live regions to be announced when observed on a background tab."

Revert "Allow aria live regions to be announced when observed on a background tab."

There have been several user complaints regarding extra announcements coming most likely from background tabs. Especially with many tabs open, this can become an issue. We should reexamine some other way to surface this type of functionality in ChromeVox Next.

The original cl was commited pre-Chrome migrated ChromeVox.

TBR=dmazzoni@chromium.org

Committed: https://crrev.com/077a6fdfc87b65a07f0c237b88c98e3447be9497
Cr-Commit-Position: refs/heads/master@{#317379}

[David Tseng, 2015-02-20 18:51:00]

dtseng@chromium.org changed reviewers:
+ dmazzoni@chromium.org

[David Tseng, 2015-02-20 19:29:52]

The CQ bit was checked by dtseng@chromium.org

[commit-bot: I haz the power, 2015-02-20 19:30:23]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/944063002/1

[commit-bot: I haz the power, 2015-02-20 19:51:37]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-20 19:52:25]

Patchset 1 (id:??) landed as
https://crrev.com/077a6fdfc87b65a07f0c237b88c98e3447be9497
Cr-Commit-Position: refs/heads/master@{#317379}