[Download Notification] Clean Up: Initialize properties in header file

[Download Notification] Clean Up: Initialize properties in header file

This patch is just a cleanup. No functionality is changed.

BUG=none
TEST=none

Committed: https://crrev.com/87ff1a73459d5f79213db5f6bcbf8ae4b70b2ffe
Cr-Commit-Position: refs/heads/master@{#329822}

[yoshiki, 2015-05-12 14:54:32]

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

[yoshiki, 2015-05-12 15:22:49]

Asanka, PTAL.

[asanka, 2015-05-14 04:08:26]

lgtm

[yoshiki, 2015-05-14 06:03:30]

The CQ bit was checked by yoshiki@chromium.org

[commit-bot: I haz the power, 2015-05-14 06:03:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1129023005/1

[commit-bot: I haz the power, 2015-05-14 07:50:28]

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

[commit-bot: I haz the power, 2015-05-14 07:50:29]

Try jobs failed on following builders:
  mac_chromium_rel_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[yoshiki, 2015-05-14 07:55:49]

The CQ bit was checked by yoshiki@chromium.org

[commit-bot: I haz the power, 2015-05-14 07:55:58]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1129023005/1

[commit-bot: I haz the power, 2015-05-14 09:28:48]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-14 09:29:42]

Patchset 1 (id:??) landed as
https://crrev.com/87ff1a73459d5f79213db5f6bcbf8ae4b70b2ffe
Cr-Commit-Position: refs/heads/master@{#329822}