Update the notification status-bar icons.

Update the notification status-bar icons.

The new icons are slightly larger than the previous version, per the
feedback we received from various reviews.

BUG=460042
Committed: https://crrev.com/e7a4e695a3298e2e960f6bcc19679df89fc85565
Cr-Commit-Position: refs/heads/master@{#317576}

[Peter Beverloo, 2015-02-20 19:31:45]

peter@chromium.org changed reviewers:
+ newt@chromium.org

[Peter Beverloo, 2015-02-20 19:31:46]

+newt for resource OWNERS

These were cut by Rebecca.

[newt (away), 2015-02-20 20:06:23]

codereview shows these images as white squares. As long as they aren't just
white squares, lgtm.

[Peter Beverloo, 2015-02-23 12:14:56]

On 2015/02/20 20:06:23, newt wrote:
> codereview shows these images as white squares. As long as they aren't just
> white squares, lgtm.

They're white-on-transparent bell icons, so yeah, that's expected. You can
change the background colour of the <div> to black to see them clearly :-).
Thanks!

[Peter Beverloo, 2015-02-23 12:14:59]

The CQ bit was checked by peter@chromium.org

[commit-bot: I haz the power, 2015-02-23 12:15:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/946673002/1

[commit-bot: I haz the power, 2015-02-23 12:54:54]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-23 12:55:27]

Patchset 1 (id:??) landed as
https://crrev.com/e7a4e695a3298e2e960f6bcc19679df89fc85565
Cr-Commit-Position: refs/heads/master@{#317576}