[Android] Reduce visibility of Tab#getTabObservers.

[Android] Reduce visibility of Tab#getTabObservers.

By being public, it was too easy for an external class to
broadcast all sort of tab notifications.  By being protected,
it is restricted to the dependent classes within the tab package.

BUG=

Committed: https://crrev.com/e4d0e88719f3f078e62f521558d3ed10c0250b3b
Cr-Commit-Position: refs/heads/master@{#434673}

[Ted C, 2016-11-23 00:28:45]

tedchoc@chromium.org changed reviewers:
+ yusufo@chromium.org

[Ted C, 2016-11-23 00:28:46]

PTAL

[Yusuf, 2016-11-24 00:12:36]

lgtm

[Ted C, 2016-11-24 00:15:32]

The CQ bit was checked by tedchoc@chromium.org

[commit-bot: I haz the power, 2016-11-24 00:16:19]

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, 2016-11-24 02:17:53]

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

[commit-bot: I haz the power, 2016-11-24 02:17:54]

Try jobs failed on following builders:
  blimp_linux_dbg on master.tryserver.chromium.linux (JOB_TIMED_OUT, no build
URL)
  chromeos_amd64-generic_chromium_compile_only_ng on
master.tryserver.chromium.linux (JOB_TIMED_OUT, no build URL)
  chromeos_daisy_chromium_compile_only_ng on master.tryserver.chromium.linux
(JOB_TIMED_OUT, no build URL)
  chromium_presubmit on master.tryserver.chromium.linux (JOB_TIMED_OUT, no build
URL)
  linux_chromium_clobber_rel_ng on master.tryserver.chromium.linux
(JOB_TIMED_OUT, no build URL)
  linux_chromium_compile_dbg_ng on master.tryserver.chromium.linux
(JOB_TIMED_OUT, no build URL)
  linux_chromium_rel_ng on master.tryserver.chromium.linux (JOB_TIMED_OUT, no
build URL)

[Ted C, 2016-11-28 16:54:20]

The CQ bit was checked by tedchoc@chromium.org

[commit-bot: I haz the power, 2016-11-28 16:54:40]

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, 2016-11-28 17:24:45]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1480352060409300, "parent_rev":
"3f99fc8964d5539f682d76d3c8cc584934878cc2", "commit_rev":
"cf3d13294386a0bd29c0c50f215454d82ef1fd1f"}

[commit-bot: I haz the power, 2016-11-28 17:25:18]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-11-28 17:27:24]

Description was changed from

==========
[Android] Reduce visibility of Tab#getTabObservers.

By being public, it was too easy for an external class to
broadcast all sort of tab notifications.  By being protected,
it is restricted to the dependent classes within the tab package.

BUG=
==========

to

==========
[Android] Reduce visibility of Tab#getTabObservers.

By being public, it was too easy for an external class to
broadcast all sort of tab notifications.  By being protected,
it is restricted to the dependent classes within the tab package.

BUG=

Committed: https://crrev.com/e4d0e88719f3f078e62f521558d3ed10c0250b3b
Cr-Commit-Position: refs/heads/master@{#434673}
==========

[commit-bot: I haz the power, 2016-11-28 17:27:24]

Patchset 1 (id:??) landed as
https://crrev.com/e4d0e88719f3f078e62f521558d3ed10c0250b3b
Cr-Commit-Position: refs/heads/master@{#434673}