Revert 243623 "Revert profile cleanup temporarily to verify regr..."

The perf results didn't change after reverting this CL so I am going to
bring it back in.

> Revert profile cleanup temporarily to verify regression is really caused by it.
> 
> BUG=310934
> TEST=Let's see what the chrome-rel-mac6 bot has to say about this.
> 
> Review URL: https://codereview.chromium.org/128413003

TBR=pastarmovj@chromium.org

Review URL: https://codereview.chromium.org/134733006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246019 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246019