[Chromecast] Simplify CastMediaBlocker.

[Chromecast] Simplify CastMediaBlocker.

Remove WebContentsObserver from CastMediaBlocker.

BUG=660331
Committed: https://crrev.com/3c3526bb1e5d954c7194ff44a7109c3bf77df49c
Cr-Commit-Position: refs/heads/master@{#435647}

[derekjchow1, 2016-11-29 21:19:50]

The CQ bit was checked by derekjchow@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-11-29 21:20:52]

Dry run: 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, 2016-11-29 23:05:29]

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

[commit-bot: I haz the power, 2016-11-29 23:05:29]

Dry run: This issue passed the CQ dry run.

[derekjchow1, 2016-11-29 23:08:36]

derekjchow@chromium.org changed reviewers:
+ halliwell@chromium.org

[halliwell, 2016-12-01 17:42:13]

On 2016/11/29 23:08:37, derekjchow1 wrote:

lgtm

[derekjchow1, 2016-12-01 17:45:28]

The CQ bit was checked by derekjchow@chromium.org

[commit-bot: I haz the power, 2016-12-01 17:45:43]

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, 2016-12-01 17:58:46]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1480614328071380, "parent_rev":
"17bec9a1c80cb420aa19dd3d93afc3ca5d96b749", "commit_rev":
"1e48d83cad2e18594f30f3d2f92c445bd8a10a76"}

[commit-bot: I haz the power, 2016-12-01 17:59:13]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-12-01 18:01:34]

Description was changed from

==========
[Chromecast] Simplify CastMediaBlocker.

Remove WebContentsObserver from CastMediaBlocker.

BUG=660331
==========

to

==========
[Chromecast] Simplify CastMediaBlocker.

Remove WebContentsObserver from CastMediaBlocker.

BUG=660331

Committed: https://crrev.com/3c3526bb1e5d954c7194ff44a7109c3bf77df49c
Cr-Commit-Position: refs/heads/master@{#435647}
==========

[commit-bot: I haz the power, 2016-12-01 18:01:35]

Patchset 1 (id:??) landed as
https://crrev.com/3c3526bb1e5d954c7194ff44a7109c3bf77df49c
Cr-Commit-Position: refs/heads/master@{#435647}