Revert of Adding strict mode for bookmark_manager file for better error checking.

Revert of Adding strict mode for bookmark_manager file for better error checking. (patchset #1 id:1 of https://codereview.chromium.org/1115683002/)

Reason for revert:
> LGTM assuming this doesn't trigger any errors :)

It did on the closure bots. Given that this change is solely about better error checking and it's hampering our ability to do compile-time checking with closure compiler, I'm reverting.

deepak.m1@: you may consider adding these statement inside of a scope (e.g. inside cr.define()) as we do a lot of file concatenation and some files might not work with strict mode.

Here's how you check if closure compiler likes your change locally:
https://code.google.com/p/chromium/wiki/ClosureCompilation

Original issue's description:
> Adding strict mode for bookmark_manager file for better error checking.
>
> Adding strict mode to bookmark manager's js files to detect error at load time itself.
>
> BUG=177166
>
> Committed: https://crrev.com/66c786a59403f02dc49df0090cece8e0e3cc3b1b
> Cr-Commit-Position: refs/heads/master@{#327679}

TBR=bauerb@chromium.org,deepak.m1@samsung.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=177166
Committed: https://crrev.com/55ca7b8160d679f0662e9e205824ae1a53f87a5c
Cr-Commit-Position: refs/heads/master@{#327819}

[Dan Beam, 2015-04-30 22:29:36]

Created Revert of Adding strict mode for bookmark_manager file for better error
checking.

[commit-bot: I haz the power, 2015-04-30 22:30:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1117143002/1

[commit-bot: I haz the power, 2015-04-30 22:41:00]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-30 22:41:55]

Patchset 1 (id:??) landed as
https://crrev.com/55ca7b8160d679f0662e9e205824ae1a53f87a5c
Cr-Commit-Position: refs/heads/master@{#327819}