Revert of Adds AL logging for Blink core events. (https://codereview.chromium.org/349263002/)

Reason for revert:
This is blocking the blink roll (https://codereview.chromium.org/346333005/) as it makes the test AdInjectionBrowserTest.DetectAdInjections in browser_tests fail

Original issue's description:
> Enables Activity Logger to log extension adding the following elements to the DOM:
> - script
> - link
> - anchor
> - iframe
> - form
> - input
> - button
> 
> BUG=388287
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=177105

TBR=mvrable@chromium.org,haraken@chromium.org,pfeldman@chromium.org,pmarch@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=388287

Review URL: https://codereview.chromium.org/355363002

git-svn-id: svn://svn.chromium.org/blink/trunk@177194 bbb929c8-8fbe-4397-9dbb-9b2b20218538