[Media Router UI] Fix search results overflow scroll and input focus.

[Media Router UI] Fix search results overflow scroll and input focus.

This change fixes the following issues:
 - The full search result list is not accessible when scrolling is necessary.
 - The input focus logic is broken by keyboard tabbing wrapping around the
   document.

BUG=594789
R=apacible@chromium.org

Committed: https://crrev.com/aa85d103c33578539738cb88f163f33deb344266
Cr-Commit-Position: refs/heads/master@{#381272}

[btolsch, 2016-03-14 22:49:03]

PTAL, thanks!

[apacible, 2016-03-15 17:18:12]

lgtm

[btolsch, 2016-03-15 17:37:39]

The CQ bit was checked by btolsch@chromium.org

[commit-bot: I haz the power, 2016-03-15 17:37:59]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1801983003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1801983003/1

[commit-bot: I haz the power, 2016-03-15 19:01:00]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-03-15 19:02:58]

Description was changed from

==========
[Media Router UI] Fix search results overflow scroll and input focus.

This change fixes the following issues:
 - The full search result list is not accessible when scrolling is necessary.
 - The input focus logic is broken by keyboard tabbing wrapping around the
   document.

BUG=594789
R=apacible@chromium.org
==========

to

==========
[Media Router UI] Fix search results overflow scroll and input focus.

This change fixes the following issues:
 - The full search result list is not accessible when scrolling is necessary.
 - The input focus logic is broken by keyboard tabbing wrapping around the
   document.

BUG=594789
R=apacible@chromium.org

Committed: https://crrev.com/aa85d103c33578539738cb88f163f33deb344266
Cr-Commit-Position: refs/heads/master@{#381272}
==========

[commit-bot: I haz the power, 2016-03-15 19:02:59]

Patchset 1 (id:??) landed as
https://crrev.com/aa85d103c33578539738cb88f163f33deb344266
Cr-Commit-Position: refs/heads/master@{#381272}