Revert of [Autofill] Enable Autofill for dynamically created forms.

Revert of [Autofill] Enable Autofill for dynamically created forms. (https://codereview.chromium.org/242613006/)

Reason for revert:
Broke DataDrivenHeuristics03 on the Mac debug bots:

http://build.chromium.org/p/chromium.mac/buildstatus?builder=Mac%2010.6%20Tests%20%28dbg%29%284%29&number=40752
http://build.chromium.org/p/chromium.mac/buildstatus?builder=Mac%2010.7%20Tests%20%28dbg%29%284%29&number=23124

Original issue's description:
> [Autofill] Enable Autofill for dynamically created forms.
> 
> The appropriate hooks with Blink already exist, this change just causes
> the browser to be informed whenever a form is added or changed.
> 
> BUG=360904
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=268107

NOTRY=true
NOTREECHECKS=true
TBR=tsepez,isherman,gcasto

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=268113

[DaleCurtis, 2014-05-04 18:32:58]

Created Revert of [Autofill] Enable Autofill for dynamically created forms.

[DaleCurtis, 2014-05-04 18:34:06]

The CQ bit was checked by dalecurtis@chromium.org

[commit-bot: I haz the power, 2014-05-04 18:34:17]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/dalecurtis@chromium.org/265203002/1

[commit-bot: I haz the power, 2014-05-04 18:34:44]

Change committed as 268113