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

Review URL: https://codereview.chromium.org/1117143002

Cr-Commit-Position: refs/heads/master@{#327819}