Revert 246216 "Add polymer-selector and polymer-selection to pol..."

> Add polymer-selector and polymer-selection to polymer.
> 
> These polymer UI components are needed for the PDF extension.
> 
> BUG=303491
> R=bshe@chromium.org, koz@chromium.org
> 
> Review URL: https://codereview.chromium.org/141483005

TBR=raymes@google.com

Review URL: https://codereview.chromium.org/139693003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246236 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246236