[Audio Player] Remove durationChanged hander in 'control-panel' element

[Audio Player] Remove durationChanged hander in 'control-panel' element

It's no longer necessary. And the handler is fired unexpected timing after unminimized and causes the issue (see the issue for detail). This patch removes it.

BUG=462065
TEST=browsertest passes

Committed: https://crrev.com/c6bb664d869cc9189e322c0b0a1bcf45d9f9adce
Cr-Commit-Position: refs/heads/master@{#321357}

[yoshiki, 2015-03-19 09:02:03]

yoshiki@chromium.org changed reviewers:
+ fukino@chromium.org

[yoshiki, 2015-03-19 09:02:24]

@fukino-san, PTAL. Thanks.

[fukino, 2015-03-19 12:08:30]

lgtm

[yoshiki, 2015-03-19 14:22:49]

The CQ bit was checked by yoshiki@chromium.org

[commit-bot: I haz the power, 2015-03-19 14:23:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1018953002/1

[commit-bot: I haz the power, 2015-03-19 14:49:57]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-19 14:50:56]

Patchset 1 (id:??) landed as
https://crrev.com/c6bb664d869cc9189e322c0b0a1bcf45d9f9adce
Cr-Commit-Position: refs/heads/master@{#321357}