ViewportChangeListener deregister and reregister on DOM changes.

ViewportChangeListener deregister and reregister on DOM changes.

BUG=402263, 402218
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=179937

[Mike West, 2014-08-11 10:05:05]

Looks reasonable. As I mentioned, I'm interested in the perf impact of doing
this work on every insert/removal. I don't expect it to be large, but do keep an
eye on the perf bots.

LGTM.

[Yoav Weiss, 2014-08-11 10:10:44]

On 2014/08/11 10:05:05, Mike West wrote:
> Looks reasonable. As I mentioned, I'm interested in the perf impact of doing
> this work on every insert/removal. I don't expect it to be large, but do keep
an
> eye on the perf bots.

Will do. Since m_listener only exists when srcset has 'w' descriptors and the
sizes value is dependent on the viewport, I don't think it should have a
significant impact, but I'll watch the bots.

> 
> LGTM.

Thanks :)

[Yoav Weiss, 2014-08-11 10:10:49]

The CQ bit was checked by yoav@yoav.ws

[commit-bot: I haz the power, 2014-08-11 10:11:03]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/yoav@yoav.ws/455333002/20001

[commit-bot: I haz the power, 2014-08-11 11:27:16]

Change committed as 179937