[Custom Tabs] Make location bar always anchor left

[Custom Tabs] Make location bar always anchor left

In customtabstoolbar we set the left margin of location bar to be the
same size of the security icon. However it the security icon is not
visible, this margin should be reset.

BUG=512161
Committed: https://crrev.com/bfc410199004d6b2a7051406fab833e5e7c35596
Cr-Commit-Position: refs/heads/master@{#339755}

[Ian Wen, 2015-07-20 20:47:46]

ianwen@chromium.org changed reviewers:
+ yusufo@chromium.org

[Ian Wen, 2015-07-21 20:53:26]

ianwen@chromium.org changed reviewers:
+ tedchoc@chromium.org

[Ian Wen, 2015-07-21 20:53:26]

ptal at this tiny CL. :P

[Yusuf, 2015-07-21 21:05:44]

lgtm

[Ian Wen, 2015-07-21 21:10:06]

The CQ bit was checked by ianwen@chromium.org

[commit-bot: I haz the power, 2015-07-21 21:12:05]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1247513002/1

[commit-bot: I haz the power, 2015-07-21 21:54:55]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-21 21:55:50]

Patchset 1 (id:??) landed as
https://crrev.com/bfc410199004d6b2a7051406fab833e5e7c35596
Cr-Commit-Position: refs/heads/master@{#339755}